Jaguar AJ-V8 User Manual

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Published by Service Communications, Jaguar Cars Limited

Publication Part No JJM 18 15 15/70, August 1996

Technical Guide

AJ-V8 Engine

and

5HP24 Transmission

Introduction

PrefaceAJ-V8/5HP24

This Technical Guide introduces the new AJ V8 engine and 5HP24 transmission installed in the XK8 Sports car. It is intended to give Jaguar Dealer workshop personnel an overview of their construction and operation, and is for information purposes only. The contents of this Technical Guide must not be used as a reference source for servicing procedures; all servicing procedures must be in accordance with the appropriate Service Manual.

This Technical Guide will not be updated. While every effort is made to ensure accuracy, changes may occur between going to press and the equipment being introduced to the market. Once the equipment is in service, details of changes can be obtained from Service Bulletins and revisions to the Service Manuals.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form, electronic, mechanical, photocopying, recording or other means without prior written permission from the Service Division of Jaguar Cars Limited.

Contents AJ-V8/5HP24

Subject Page

Glossary

Abbreviations 2

Introduction 3

Engine

Basic Engine 5 Engine Cooling 17 Engine Lubrication 20 Variable Valve Timing 24 Air Intake System 27 Fuel System 33 Ignition System 35 Crankcase Ventilation 35 EGR System 37 Engine Accessories 38 Accessory Drive 39 Engine Harness 41 Engine Covers 42 Engine Specifications 43

Engine Management

ECM 45 Electronic Throttle 53 Fuel Pump 58 Fuel Injection 58 Ignition 59 EVAP System 60 Variable Valve Timing 61 EGR System 61 Engine Starting 61 HO2S Heaters 62 Instrument Cluster 62 A/C Compressor Clutch 62 Windshield and Backlight Heaters 62 Radiator Cooling Fans 62 Diagnostics 63

Transmission

Introduction 65 Technical Data 66 Gearshifting 66 Mechanical Description 66 Electrical Description 67

Transmission Management

Transmission Management 68

Service Tools

New Tools 72

GlossaryAJ-V8/5HP24

The following abbreviations are used in this document:

Abbreviation Description

ABS anti-lock braking system A/C air conditioning A/CCM air conditioning control module BPM body processor module BHP brake horse power ˚C degree Celsius CAN controller area network CDI cubic inch displacement DIN Deutsche Institut für Normung dc direct current DTC diagnostic trouble code ECM engine control module ECT engine coolant temperature EGR exhaust gas recirculation EMS engine management system EVAP evaporative emission ˚F degree Fahrenheit ft foot HO2S heated oxygen sensor in inch JDS Jaguar diagnostic system lb pound lbf.ft pound force feet kg kilogram km/h kilometer per hour kW kilowatt m meter MAFS mass air flow sensor MIL malfunction indicator lamp mph miles per hour mm millimeter ms millisecond Nm Newton meter NOx nitrous oxide OBD on-board diagnostics O2S oxygen sensor PAS power assisted steering PDU portable diagnostic unit psi pounds per square inch PTFE polytetrafluoroethane rpm revolutions per minute SAE Society of Automotive Engineers (USA) SCP standard corporate protocol TCM transmission control module USA United States of America V volt VSV vacuum solenoid valve

Introduction AJ-V8/5HP24

The AJ-V8 4.0 litre, engine is the first of a new family of Jaguar engines. Designed to give excellent performance, refinement, economy and low vibration levels it also conforms to the strictest emission legislation. Weighing only 200 kilograms (441 lb), the engine is shorter by 12 inches (300 mm) than the current AJ16 4.0 litre engine. Compression ratio is 10.75:1, with four valves per cylinder. The cylinder heads, block and bedplate are all cast aluminum. Cylinders have electro-plated bores which reduce piston friction, improve warm-up and oil retention. A variable valve timing system has been introduced to give improved low and high-speed engine performance and excellent idle quality. The valve gear is chain driven for durability. Low valve overlap improves engine idle speed and low residual fuel levels which improves combustion and reduces hydrocarbon emissions. The inlet manifold is a one-piece, composite moulding with integral fuel rails connecting to the eight side feed fuel injectors. Air flow into the engine is via an electronic throttle assembly. Movement of the throttle is controlled by sensors in the throttle assembly through the ECM. The engine has a low volume, high velocity, cooling system which achieves a very fast warm-up with reduced and even metal temperatures in the combustion chamber and increased bore temperatures. The generator, A/C pump, and PAS pump are mounted to the cylinder block on rigid cradle supports. Accessory drive is from a single, 7-ribbed vee belt. Hydraulic engine mounts minimise noise and vibration. A new engine management system adjusts fuel and ignition settings, monitors and controls exhaust emissions and provides an on-board diagnostic capability.

The transmission is a new ZF 5-speed, automatic, electronically controlled unit. The unit is oil filled for life so does not have an oil gauge (dipstick). Two driver selected modes are available, sport or normal. The TCM is programmed with cruise, traction, gradient, warm-up and hot mode features. It also provides an on-board diagnostic capability.

The engine and transmission meet OBDII USA environmental regulations. Default limp home modes for both engine and transmission are provided.

Engine AJ-V8/5HP24

Basic Engine

The AJ-V8 is an all new 90° V8 liquid cooled engine that gives refined and effortless performance. Constructed in aluminum alloy, the AJ-V8 introduces several innovative design features new to Jaguar engines, the most notable of these being:

• a bedplate

• nikasil coated cylinder bores

• fracture split connecting rods

• variable valve timing

• aluminum alloy valve lifters

• electronic throttle control.

303-056

EngineAJ-V8/5HP24

ENGINE STRUCTURE

ENGINE DATA LOCATIONS

303-052

303-001

Cylinder Block

The cylinder block is an "enclosed V" design, which provides an inherently rigid structure with good vibration levels. Nikasil (a composition of nickel and silicon) coated cylinder bores provide good friction, heat transfer and piston noise levels. A low volume coolant jacket improves warm-up times and piston noise levels; the longitudinal flow design of the jacket, with a single cylinder head coolant transfer port in each bank, improves rigidity and head gasket sealing. The right hand cylinder bank is designated as "A" bank, and the left hand as "B" bank. The cylinder bores of each bank are numbered from 1 to 4, starting from the front. Engine data is marked at three locations on the cylinder block. Component diameters are represented by alphabetical and numerical codes; keys to the codes are in the Service Manual.

1. Cylinder Head

2. Cylinder Block

3. Bed Plate

4. Structural Sump

Emissions Code

Serial Number

* Main Bearing Crankshaft Diameters * Connecting Rod Bearing Crankshaft Diameters * Cylinder Bore Diameters * Main Bearing Bore Diameters *

Engine AJ-V8/5HP24

CYLINDER BLOCK, CRANKSHAFT AND BEDPLATE

303-011

EngineAJ-V8/5HP24

Bedplate

The bedplate is a structural casting bolted to the bottom of the cylinder block to retain the crankshaft. The use of a bedplate further improves rigidity. Iron inserts, cast into the main bearing supports of the bedplate, minimise main bearing clearance changes due to heat expansion. Two hollow dowels align the bedplate with the cylinder block. Beads of sealant seal the joint between the bedplate and the cylinder block.

Crankshaft

Six counter-balance weights ensure good vibration levels from the four throw, five bearing crankshaft. Manufactured in cast iron, the crankshaft also has undercut and rolled fillets for improved strength. The main bearings are aluminum/tin split plain bearings. An oil groove in the top half of each bearing transfers oil into the crankshaft for lubrication of the connecting rod bearings. A lead/bronze thrust washer is installed each side of the top half of the center main bearing. The crankshaft rear oil seal (a lip seal similar to that used on the AJ16 engine) is a press fit in the bedplate to cylinder block interface.

SEALANT TRACK ON BEDPLATE

303-012

CRANKSHAFT REAR OIL SEAL

303-013

Engine AJ-V8/5HP24

Connecting Rods and Pistons

The connecting rods are manufactured in sinter forged steel. The bearing caps are produced by fracturing the opposing sides of the connecting rod at the bearing horizontal center-line. As well as being easier to manufacture, when re-assembled the fractured surfaces interlock to form a strong seamless joint. The cylinder position is etched on adjoining sides of the joint to identify matching connecting rods and bearing caps. The connecting rod bearings are lead/bronze split plain bearings. The pistons are of the open ended skirt design with flat upper surfaces to reduce heat absorbtion. Three piston rings, two compression and one oil control, are installed on each piston. Each piston is installed on a wrist pin located in a lead/bronze bushing in the connecting rod.

Sump

The sump consists of an aluminum alloy structural sump bolted to the bedplate, and a pressed steel oil pan bolted to the structural sump. A windage tray attached to the top of the structural sump isolates the oil pan from the disturbed air produced by the rotation of the crankshaft, to prevent oil aeration and improve oil drainage. A rubber plug at the rear of the structural sump seals the port that provides access to the torque converter securing bolts. The engine oil drain plug is located at the front right corner of the oil pan. A silicon rubber in-groove gasket seals the joint between the oil pan and the structural sump; a bead of sealant seals the joint between the structural sump and the bedplate.

CONNECTING ROD AND PISTON

303-014

SEALANT TRACK ON STRUCTURAL SUMP

303-021

EngineAJ-V8/5HP24

Starter and Drive Plate

The engine starter motor is installed at the rear right side of the engine, at the cylinder block to bedplate split line (for further details of the starter motor see Technical Guide, XK8 Introduction). The starter drive plate is attached to the rear of the crankshaft. A timing disc, for the engine speed sensor, is spot welded to the front face of the drive plate.

STRUCTURAL SUMP AND OIL PAN

STARTER MOTOR

303-062

Torque Converter Access

303-010

Engine AJ-V8/5HP24

Cylinder Heads

The cylinder heads are unique to each cylinder bank. Deep seated bolts, to reduce distortion, secure the cylinder heads to the cylinder block. Two hollow dowels align each cylinder head with the cylinder block. The cylinder head gaskets consist of a silicon beaded composite gasket with metal eyelets for the cylinder bores, similar to that on the AJ16 engine. Each cylinder head incorporates dual overhead camshafts operating four valves per cylinder via solid aluminum alloy valve lifters. Steel shims in the top of the valve lifters enable adjustment of valve clearances. The lightweight valve gear provides good economy and noise levels. Valve head diameters are 31mm (1.220 in) for the exhaust and 35mm (1.378 in) for the intake. All valves have 5mm (0.197 in) diameter stems supported in sintered metal seats and guide inserts. Collets, valve collars and spring seats locate single valve springs on both intake and exhaust valves. Valve stem seals are integrated into the spring seats. The camshafts are manufactured in chilled cast iron. Five aluminum alloy caps retain each camshaft. Location numbers, 0 to 4 for the intake camshaft and 5 to 9 for the exhaust camshaft, are marked on the outer faces of the caps. The rear of B bank intake camshaft has a timing ring for the camshaft position sensor. A flat, machined near the front of each camshaft, enables the camshafts to be locked during the valve timing procedure.

CAMSHAFT POSITION SENSOR TIMING RING

303-054

The 14 mm spark plugs, one per cylinder, locate in recesses down the center-line of each cylinder head. An engine lifting eye is cast into the front of each cylinder head (the rear lifting eyes, one on each cylinder head, are bolt-on tools).

TIMING DISC

STARTER DRIVE PLATE

303-035

303-034

EngineAJ-V8/5HP24

Timing Gear

Single row primary and secondary chains drive the camshafts of each cylinder bank. The primary chains transmit the drive from two sprockets on the crankshaft to variable valve timing units on the intake camshafts. The secondary chains transmit the drive from the variable valve timing units to sprockets on the exhaust camshafts.

A BANK CYLINDER HEAD

303-047

Lifting Eye

Intake Camshaft

Exhaust Camshaft

(Continued on Page 14)

Engine AJ-V8/5HP24

303-016 / 017

Primary Chain Tensioner

Secondary Chain Tensioner

Secondary Chain

Variable Valve Timing Unit

Primary Chain

TIMING GEAR

EngineAJ-V8/5HP24

A key locates the two drive sprockets on the crankshaft. The crankshaft's torsional vibration damper retains the sprockets in position. The variable valve timing units and the exhaust camshaft sprockets are non-interference, nonkeyed fits on their respective camshafts; the drive being transmitted by the face to face friction load produced by the valve timing unit/sprocket securing bolt. Each chain has an hydraulic tensioner operated by engine oil. A jet of oil from the end of each tensioner lubricates the chains. The primary chain tensioners act on pivoting flexible tensioner blades. The secondary chain tensioners act directly on the chains. Guide rails are installed on the drive side of the primary chains.

Timing Cover

The aluminum alloy timing cover accommodates the crankshaft front oil seal (a PTFE lip seal) and the two variable valve timing solenoids. Silicon rubber in-groove gaskets seal the joint between the timing cover and the front face of the engine.

TIMING COVER

Crankshaft Front Oil Seal

303-015

Timing Gear (Continued)

Variable Valve Timing Solenoid

Engine AJ-V8/5HP24

Camshaft Covers

The camshaft covers are manufactured from vinyl ester composite. The A bank camshaft cover incorporates an outlet for the full load engine breather. The B bank camshaft cover incorporates the engine oil filler cap and an outlet for the part load engine breather. Identical oil separators are incorporated below the breather outlet in each cover (see Crankcase Ventilation, page 35). Silicon rubber in-groove gaskets seal the joints between the camshaft covers and the cylinder heads. Together with spacers and seals on the camshaft cover fasteners, they also isolate the covers from direct contact with the cylinder heads, to reduce noise.

B BANK CAMSHAFT COVER

303-042

EngineAJ-V8/5HP24

Exhaust Manifold

The thin-wall cast iron manifolds are unique for each cylinder bank. On engines with EGR, the A bank manifold has a connection for the transfer pipe. Spacers on the securing bolts allow the manifolds to expand and retract with changes of temperature while maintaining the clamping loads. Heat shields are integrated into the exhaust manifold gaskets.

EXHAUST MANIFOLD

303-023

Engine AJ-V8/5HP24

Engine Cooling

The cooling system is a low volume, high velocity system with good warm-up and temperature profile characteristics. From the pump, the coolant flows into each bank of the cylinder block. In each bank, 50% of the coolant cools the cylinder bores and 50% is diverted through a bypass gallery. At the rear of the banks the two flows mix and enter the cylinder heads. The coolant then flows forwards to the outlet ports. When the thermostat is closed, the coolant returns directly to the pump through the bypass on the thermostat housing. When the thermostat is open, the coolant returns to the pump via the vehicle's radiator. A coolant drain plug is installed on the rear left side of the cylinder block. On vehicles with the cold climate package, the cylinder block heater replaces the drain plug.

Note: Coolant is drained from the right bank of

the cylinder block by removing the coolant pipe behind the starter motor.

CYLINDER BLOCK DRAIN/HEATER

COOLING SYSTEM DIAGRAM

1. Electronic Throttle

2. EGR Valve

3. A/C Heater Return

4. Coolant Pump

5. Thermostat Housing

6. Vehicle Radiator (Reference)

7. A/C Heater Supply

8. Bleed Outlet

303-O63

303-028

EngineAJ-V8/5HP24

Coolant Pump

The coolant pump is installed between the two cylinder banks, on the front face of the cylinder block. The pumping element is a shrouded composite impeller. Coolant escapes from seal breather holes in the housing if the pump's bearing seal fails. An O-ring and an edge bonded rubber/aluminum alloy gasket seal the pump to cylinder block interface. The O-ring seals the inlet port from the thermostat. The gasket seals the outlet ports into the cylinder banks.

Thermostat Housing

The composite thermostat housing is installed between the two cylinder banks, immediately above the coolant pump. The thermostat controls the flow of coolant through the radiator. It starts to open at 80 to 84°C (176 to 183˚F) and is fully open at 96°C (205˚F). A duct in the cylinder block connects the thermostat housing outlet to the pump inlet. A stub pipe connects the duct to the air conditioning heater matrix return line. An in-groove gasket seals the joint between the thermostat housing and the cylinder block. In addition to containing the thermostat, the composite thermostat housing incorporates connections for the bleed, bypass and radiator bottom hoses. The bleed outlet vents any air in the system into the vehicle's coolant reservoir. The cap of the thermostat housing is removable, to allow air out of the system when filling from empty.

CAUTION: Use the correct torque (marked on

the cap) when re-installing the cap, or the cap/thermostat housing could be damaged.

COOLANT PUMP

303-030

THERMOSTAT HOUSING

Coolant Hoses

Supply and return hoses for the air conditioning heater matrix are installed between the cylinder banks. A connection at the rear of A bank provides the coolant supply for the electronic throttle and the EGR valve. The outlet from the EGR valve connects to the return hose of the air conditioning heater matrix.

By-pass

From Radiator

A/C Heater Return

Cap

Bleed

303-029

Engine AJ-V8/5HP24

COOLANT HOSES

A/C Heater Matrix

303-032

Electronic Throttle

EGR Valve

Electronic Throttle

EngineAJ-V8/5HP24

Engine Lubrication

Oil is drawn from the reservoir in the oil pan and pressurised by the oil pump. The output from the oil pump is then filtered and distributed through internal oil passages. All moving parts are lubricated by pressure or splash oil. Pressurised oil is also provided for operation of the variable valve timing units and the timing gear chain tensioners. The oil returns to the oil pan under gravity. Large drain holes through the cylinder heads and cylinder block ensure the quick return of the oil, reducing the volume of oil required and enabling an accurate check of the contents soon after the engine stops. System replenishment is through the oil filler cap on the B bank camshaft cover. With the exception of the pump and level gauge, all oil system components are installed on the structural sump.

Coolant Outlet Duct

The composite coolant outlet duct connects to the outlet port of each cylinder head to provide a common connection point for the radiator top hose. It also incorporates connections for the coolant temperature sensor, the supply to the air conditioning heater matrix, and the bypass flow to the thermostat housing. An in-groove gasket seals each of the joints between the outlet duct and the cylinder heads.

COOLANT OUTLET DUCT

ECT Sensor

A/C Heater Supply

By-pass

To Radiator

303-066

Engine AJ-V8/5HP24

LUBRICATION SYSTEM

1. Valve Lifter Supply

2. Main Bearing Supply

3. Connecting Rod Bearing Supply

4. Bedplate/Cylinder Block Interface

5. Oil Pick-up

6. Pressure Relief Valve

7. Oil Pressure Switch

8. Oil Filter

9. Structural Sump/Bedplate Interface

10. Bedplate/Cylinder Block Interface

11. Oil Pump

12. Primary Chain Tensioner Supply

13. Cylinder Block/Cylinder Head Interface

14. Variable Valve Timing Supply

15. Camshaft Bearing Supply

16. Secondary Chain Tensioner Supply

303-007

EngineAJ-V8/5HP24

Oil Pump

The oil pump is installed on the crankshaft at the front of the engine. The pump inlet and outlet ports align with oil passages in the bedplate. A rubber coated metal gasket seals the pump to bedplate interface. The pumping element is an eccentric rotor, which is directly driven by flats on the crankshaft. An integral pressure relief valve regulates pump outlet pressure at 4.5 bar (65.25 psi).

Oil Filter

The oil filter is a replaceable cartridge installed on an adapter. An internal bypass facility permits full flow bypass if the filter is blocked.

Oil Pressure Switch

The oil pressure switch connects a ground input to the instrument cluster when oil pressure is present. The switch operates at a pressure of

0.15 to 0.41 bar (2.2 to 5.9 psi).

Oil Level Gauge

The oil level gauge locates midway along the left side of the oil pan, supported in a tube installed in the bedplate. Two holes in the end of the gauge indicate the minimum and maximum oil levels. There is a difference of approximately 1 liter (1 US quart) between the two levels.

OIL LEVEL GAUGE

303-022

OIL PUMP

303-009

Oil Pick-up

The moulded composite oil pick-up is immersed in the oil reservoir to provide a supply to the oil pump during all normal vehicle attitudes. The castellated inlet allows the supply to be maintained even if the sump pan is deformed (eg. by “grounding”). A mesh screen in the inlet prevents debris from entering the oil system.

Engine AJ-V8/5HP24

OIL SYSTEM COMPONENTS ON STRUCTURAL SUMP

Pressure Switch

Pick-up

Filter

303-185

EngineAJ-V8/5HP24

Variable Valve Timing

The variable valve timing system improves low and high speed engine performance, engine idle quality and exhaust emission. It is a two position system that operates on the intake camshafts only. There are 30° of crankshaft movement between the retarded and advanced positions. Engine oil pressure operates the system under the control of the ECM. For each intake camshaft there is a valve timing unit, a bush carrier assembly and a valve timing solenoid.

Valve Timing Unit

The valve timing unit turns the intake camshaft in relation to the primary chain to advance and retard the timing. The unit consists of a body and sprocket assembly separated from an inner sleeve by a ring piston and two ring gears. A bolt secures the inner sleeve to the camshaft. The ring gears engage in opposing helical splines on the body and sprocket assembly and on the inner sleeve. The ring gears transmit the drive from the body

and sprocket assembly to the inner sleeve and, when moved axially, turn the inner sleeve in relation to the body and sprocket assembly. Engine oil pressure (controlled by the valve timing solenoid) moves the ring gears and piston to turn the inner sleeve in the advanced timing direction. A return spring moves the ring gears and piston to turn the inner sleeve in the retarded timing direction. Additional springs absorb backlash to reduce noise and wear. The springs between the ring gears absorb rotational backlash. The spring between the inner sleeve and the end of the body and sprocket assembly absorbs axial backlash.

Retarded Advanced

TDC

Intake

Exhaust

BDC

Exhaust

TDC

Intake

BDC

35°

5°

10°

25°

5°

VALVE TIMING DIAGRAMS

65°

50°

35°

50°

303-068

Engine AJ-V8/5HP24

Bush Carrier

The bush carrier contains oil passages that link the engine oil supply to the valve timing unit. A lug on the bush carrier locates in the central bore of the valve timing unit. Two hollow dowels at the bush carrier to cylinder block interface ensure the lug is accurately located. A scarf- jointed fibre ring seals the joint between the lug and the valve timing unit. An integral shuttle valve, biased by a coil spring, controls the flow of oil through the oil passages.

VALVE TIMING UNIT

BUSH CARRIERS

Inner Sleeve

Return Spring

Piston

Ring Gears

Body and Sprocket Assembly

303-002

303-003

EngineAJ-V8/5HP24

Valve Timing Solenoid

The valve timing solenoid controls the position of the shuttle valve in the bush carrier. A plunger on the solenoid extends when the solenoid is energised and retracts when the solenoid is deenergised.

Operation

When the valve timing solenoids are deenergised, the coil springs in the bush carriers position the shuttle valves to connect the valve timing units to drain. In the valve timing units, the return springs hold the ring pistons and gears in the retarded position. When the valve timing solenoids are energised by the ECM, the solenoid plungers position the shuttle valves to direct engine oil to the valve timing units. In the valve timing units, the oil pressure overcomes the force of the return springs and moves the gears and ring pistons to the advanced position. System response times are 1.0 second maximum for advancing and 0.7 second maximum for retarding. While the valve timing is in the retarded mode, the ECM produces a periodic lubrication pulse.

VALVE TIMING SOLENOID

VARIABLE VALVE TIMING OPERATION

Retarded

Advanced

Engine Oil Pressure

303-004

Engine Oil Pressure

303-005

Engine AJ-V8/5HP24

This momentarily energises the valve timing solenoids to allow a spurt of oil into the valve timing units. The lubrication pulse occurs once every 5 minutes.

Note: With the vehicle stationary and the hood

open, operation of the valve timing solenoids may be audible when the lubrication pulse occurs at engine idle speed.

Air Intake System

Filtered air from the vehicle's intake ducting is metered by the electronic throttle then directed through the induction elbow into the intake manifold.

AIR INTAKE SYSTEM

Intake Manifold

Electronic Throttle

Induction Elbow

303-050

EngineAJ-V8/5HP24

Electronic Throttle

The electronic throttle enables the ECM to control the flow of air into the engine. It includes:

• an input shaft that receives driver inputs from the accelerator pedal via a conventional throttle cable

• a mechanical guard, to prevent throttle valve position exceeding driver demand and to operate the throttle valve mechanically if the electronic system fails

• a vacuum actuator, to operate the mechanical guard in the cruise control mode of operation

• a throttle valve, to regulate the air flow

• a thermostatic air valve, to control a bypass flow around the throttle valve

• a dc motor, to operate the throttle valve in response to inputs from the ECM

• three position sensors, to supply the ECM with the position's of the input shaft (ie. accelerator pedal), the mechanical guard and the throttle valve

• springs connected to the input shaft, the mechanical guard, the throttle valve and the drive gear of the dc motor.

Vacuum Actuator

On vehicles with cruise control, the vacuum actuator is connected to manifold vacuum and controlled by the ECM. On vehicles without cruise control, the vacuum actuator is open to atmosphere and the actuator is inoperative.

Thermostatic Air Valve

The thermostatic air valve is a wax capsule operated valve that enables engine starting at low engine temperatures (with the accelerator pedal in the idle position, the degree of throttle valve movement available between fully closed and the mechanical guard is insufficient to start the engine at low temperatures). The thermostatic air valve is fully open at a coolant temperature of approximately -30°C (-22˚F) and progressively closes until it is fully closed at +40 °C (+104˚F). A flow of engine coolant through the throttle body provides the temperature source to operate the thermostatic air valve.

SIMPLIFIED VIEW OF ELECTRONIC THROTTLE

Throttle Valve Position Sensor

Mechanical Guard

Mechanical Guard Position Sensor

Accelerator Pedal Position Sensor

Input Shaft

303-080

Spring Force

Engine AJ-V8/5HP24

Springs

The input shaft spring and the mechanical guard spring oppose movement in the throttle open direction, and provide the "feel" of the accelerator pedal. The throttle valve spring and the drive gear spring oppose movement in the throttle closed direction.

Operation

The design of the input shaft and the mechanical guard, and the bias of their respective springs, means that, except in cruise control, they always rotate together. The throttle cable turns them in the open direction; the springs keep their adjacent levers locked together and turn them in the closed direction. The ECM monitors the position of the input shaft and mechanical guard using the inputs from the accelerator pedal and mechanical guard position sensors. During normal operation, when the ECM detects any movement it signals the dc motor to

turn the throttle valve and follow the input shaft and mechanical guard, maintaining a constant gap between the adjacent levers of the throttle valve and mechanical guard. The dc motor drive gears turn the throttle valve in the closed direction; the throttle valve spring turns the throttle valve in the open direction and keeps the throttle valve in contact with the drive gear. Inputs from the throttle valve position sensor enable the ECM to exercise closed loop control. The arrangement of the throttle valve drive prevents the ECM from exceeding driver demand, since if the motor is driven fully open the throttle valve engages the mechanical guard and disengages from the dc motor drive gears. The arrangement of the mechanical guard to throttle valve interface allows the ECM to reduce throttle opening to less than driver demand, eg. during stability/traction control or engine power limiting.

ELECTRONIC THROTTLE

Coolant Inlet

Thermostatic Air Valve

dc Motor

Coolant Outlet

Vent

Vacuum Actuator

303-067

EngineAJ-V8/5HP24

Operating Modes (Refer to the figure, page 31)

Normal

1. Throttle cable inputs driver demand

2. Input shaft turns mechanical guard

3. Sensors supply ECM with inputs of driver demand

4. ECM operates dc motor

5. Sensor supplies ECM with inputs of throttle valve position

6. Gap maintained between throttle valve and mechanical guard

Cruise Control

1. Vacuum actuator turns mechanical guard

2. Sensor supplies ECM with mechanical guard position

3. ECM operates dc motor

4. Sensor supplies ECM with inputs of throttle valve position

5. Gap maintained between throttle valve and mechanical guard

6. Input shaft at idle position, disengaged from mechanical guard

Mechanical Guard

1. Throttle cable inputs driver demand

2. Input shaft turns mechanical guard

3. Mechanical guard turns throttle valve

4. dc motor drive disengaged from throttle valve

At idle, the ECM controls engine speed using the restricted throttle valve movement available between the mechanical guard (open limit) and a factory set stop on the dc motor drive gear (closed limit). When cruise control is engaged, the ECM calculates the required throttle valve opening and operates the vacuum system connected to the vacuum actuator. The vacuum actuator then turns the mechanical guard to a position that allows the required throttle valve opening. The inputs from their respective position sensors allow the ECM to monitor and adjust the mechanical guard and the throttle valve to maintain the set speed. As the driver releases the accelerator pedal, the input shaft disengages from the mechanical guard. Note that during cruise control, when

accelerating above the set speed, the accelerator pedal has a lighter "feel" until the input shaft engages with the mechanical guard again. Mechanical operation of the throttle valve occurs if the ECM selects the mechanical guard mode of operation after detecting a fault. The ECM deenergizes the dc motor and the throttle valve spring turns the throttle valve in the open direction until it engages the mechanical guard. The input shaft, mechanical guard and throttle valve are then effectively locked together by their springs, so that the throttle cable is in direct control of the throttle valve. When the throttle valve opens, it turns the dc motor drive gears. On subsequent closing of the throttle valve the drive gears remain in the open position, disengaged from the throttle valve.

Engine AJ-V8/5HP24

ELECTRONIC THROTTLE OPERATING MODES

Normal

Mechanical Guard

Cruise Crontrol

Spring Force

303-080,/081/082

EngineAJ-V8/5HP24

Induction Elbow

The induction elbow provides the interface between the electronic throttle and the intake manifold. Connections on the induction elbow provide vacuum take-offs for various services. A boss on the rear of the elbow accommodates the EGR valve.

Intake Manifold

The intake manifold is manufactured in composite, with integrated composite fuel rails and metal thread inserts. Individual ducts lead off a central chamber to the inlet ports of each cylinder. Silicon rubber gaskets, located in channels in the intake manifold, seal the joints between the ducts and the cylinder heads.

Fuel Tank Vacuum and Pressure Relief Valve Connection

Part Load Breather/ EVAP Valve Vacuum Connection

Brake Booster Vacuum Connection

Fuel Pressure Regulator/ Cruise Control Vacuum Connection

303-033

INDUCTION ELBOW

SECTION THROUGH INTAKE MANIFOLD

303-051

Engine AJ-V8/5HP24

Fuel System

Fuel injectors, controlled by the ECM, are installed in the fuel rails on each side of the intake manifold. A cross-over pipe connects the two fuel rails together at the front of the manifold. A test valve in the cross-over pipe allows the fuel rail to be pressurised and depressurised during servicing and troubleshooting. A pressure regulator on the rear of the right fuel rail controls the pressure in the fuel rails. A return line directs excess fuel from the pressure regulator back to the fuel tank.

FUEL SYSTEM

Test Valve

Fuel Injector

Fuel Return

Intake Manifold Pressure

Fuel Pressure Regulator

303-024/059/078/155

EngineAJ-V8/5HP24

Fuel Injectors

Eight, side fed, dual straight jet, fuel injectors are installed in the fuel rails. The injectors are electromagnetic solenoid valves controlled by the ECM. Two O-rings seal each injector to manifold interface. The fuel jets from the injectors are directed onto the back of the intake valves.

Pressure Regulator

The pressure regulator is a diaphragm operated valve that regulates fuel rail pressure at 2.9 bar (42.05 psi) above intake manifold pressure.

FUEL INJECTOR

303-025

Engine AJ-V8/5HP24

Ignition System

The ignition system consists of two ECM controlled ignition amplifier modules, which each supply four spark plug mounted ignition coils. The 14 mm spark plugs, one per cylinder, locate in recesses down the center-line of each cylinder head. The on-plug ignition coils are secured to the camshaft covers. The engine harness connects the on-plug ignition coils to the ignition amplifiers located on the vehicle body. A composite cover fits over the on-plug coils.

Crankcase Ventilation

The engine is ventilated through a part load and a full load breather. The part load breather is a flexible composite hose connected between the oil separator in B bank camshaft cover and the induction elbow. A restrictor in the outlet from the oil separator prevents reverse flow. The full load breather is a flexible composite hose connected between the oil separator in A bank camshaft cover and the air intake duct. The ends of the breather hoses incorporate quick release connectors (see figure, page 36). The oil separators consist of wire gauze packed into an open ended enclosure below the breather outlet.

IGNITION COIL AND SPARK PLUG

303-049

OIL SEPARATOR

303-046

EngineAJ-V8/5HP24

CRANKCASE VENTILATION SYSTEM

Part Load Breather Hose Connector

Full Load Breather Hose Connector

303-065/077/079

Engine AJ-V8/5HP24

EGR System

The EGR system is controlled by the ECM and consists of an EGR valve and a transfer pipe. The EGR valve is a 4 pole stepper motor installed on the rear of the induction elbow. The valve is cooled by the coolant return from the electronic throttle. The transfer pipe connects the right exhaust manifold to the EGR valve.

EGR VALVE AND TRANSFER PIPE

303-048

EngineAJ-V8/5HP24

Engine Accessories

All engine accessories are rigidly mounted to improve refinement, ie. there are no shock mounts. Accessory mounting brackets on the left and right sides of the engine support the A/C compressor/ PAS pump and the generator respectively. Dowels between the accessory mounting brackets and the engine ensure the accessory pulleys are accurately aligned with the accessory drive belt (for further details of the accessories see Technical Guide, XK8 Introduction).

ACCESSORY MOUNTING BRACKETS

303-019

Engine AJ-V8/5HP24

Replace Belt

New Belt Maximum Length

New Belt Minimum Length

Belt Wear

Indicator

AUTOMATIC TENSIONER

Accessory Drive

A single seven ribbed belt drives all the engine mounted accessories. The torsional vibration damper on the front of the crankshaft drives the belt. An automatic tensioner, located on the left accessory mounting bracket, keeps the belt at the correct tension. An idler pulley on the right accessory mounting bracket increases the wrap angle around the generator pulley. The torsional vibration damper incorporates compressed rubber between its inner and outer diameters to absorb vibration and shock loads. The automatic tensioner consists of an idler pulley on the end of a spring loaded pivot arm. The pivot arm can be turned counter-clockwise (viewed from the front of the engine) for removal and installation of the belt. A belt wear indicator is incorporated on the rear of the pivot arm.

PAS Pump

A/C Compressor

Generator

303-018

ENGINE ACCESSORIES AND DRIVE BELT

303-020

EngineAJ-V8/5HP24

Connectors

1. PI032, B Bank VVT solenoid

2. PI027, B Bank Knock Sensor

3. PI004, Engine Coolant Temperature Sensor

4. PI026, A Bank Knock Sensor

5. PI031, A Bank Valve Timing Solenoid

6. PI035, MAFS (On vehicle)

7. PI050, Generator

8. PI040, Oil Pressure Switch

9. PI018-PI021, A Bank Ignition Coils 1-4 PI022-PI025, B Bank Ignition Coils 1-4

10. PI006, Throttle Position Sensor

ENGINE HARNESS

11. PI002, Engine Management Harness (On vehicle)

12. PI001, Engine Management Harness (On vehicle)

13. PI033, Throttle Valve Motor

14. PI034, EGR Valve

15. PI015, Camshaft Position Sensor

16. PI042, Accelerator Pedal and Mechanical Guard Position Sensors

17. PI007-PI010, A Bank Injectors 1-4 PI011-PI014, B Bank Injectors 1-4

18. PI037, A/C Compressor Lock Sensor

19. PI036, A/C Compressor Clutch

20. PI017, Engine Speed Sensor

303-057

Engine AJ-V8/5HP24

Engine Harness

The engine harness links engine mounted electrical components to the vehicle's engine management harness. The connectors that interface with the engine management harness are attached to a bracket on the transmission housing. Integral nylon fasteners attach the harness to the engine. Connectors on component flying leads are attached to engine mounted brackets.

CONNECTORS ON TRANSMISSION HOUSING BRACKET

303-061

HARNESS FASTENER

303-064

FLYING LEAD CONNECTOR BRACKET

303-058

EngineAJ-V8/5HP24

Engine Covers

Engine covers are installed over the fuel injectors. The covers are a push fit, held in position by mating studs and grommets on the covers and the engine. The rubber grommets isolate the covers from the engine to prevent noise. A sleeve connects the covers together at the rear.

ENGINE COVERS

MOUNTING POINTS ON ENGINE COVER

MOUNTING POINTS ON ENGINE

303-055

303-040

303-039

Engine AJ-V8/5HP24

Engine Specifications

Configuration 90° V8 Cylinder Head Dual overhead camshafts, 4 valves per cylinder Valve Clearances (Cold):

Intake 0.18 to 0.22 mm (0.007 to 0.009 in)

Exhaust 0.23 to 0.27 mm (0.009 to 0.011 in) Spark Plug Type: NGK PFR5011E (platinum tipped center electrode) Spark Plug Gap: 1.0 mm (0.040 in) Firing Order 1A, 1B, 4A, 2A, 2B, 3A, 3B, 4B Bore 86 mm (3.386 in) Stroke 86 mm (3.386 in) Displacement 3.996 liters (244 CDI) Compression Ratio 10.75 : 1 Maximum Power (DIN) 216 kW (290 BHP) at 6100 rpm Maximum Torque (DIN) 393 Nm (290 lbf. ft) at 4250 rpm Maximum Speed (Limited) 7100 rpm Coolant Type Water and Jaguar anti-freeze to specification ESD-M97B49-A

(see Service Manual for mixture ratio)

Coolant Volume:

Engine Only 3.7 liters (0.98 US gallon)

Complete System 10 liters (2.65 US gallons) Oil Specification: SAE 5W30 - API SH/ILSAC GF-2 Oil Volume: 6.5 liters (6.88 US quarts) Weight (With Accessories) Approximately 200 kg (441 lb)

Engine ManagementAJ-V8/5HP24

ECM

The engine management system is controlled by the ECM, which is installed in the control module enclosure in the engine compartment. The ECM provides optimum control of the engine under all operating conditions. It also incorporates a comprehensive monitoring and diagnostic capability. Software variations ensure that the system complies with the latest diagnostic and emissions legislation of the destination market. The ECM receives inputs from engine related sensors and various vehicle systems, and provides outputs for the following:

• electronic throttle

• fuel pump

• fuel injection

• ignition

• EVAP system

• variable valve timing

• EGR system

• engine starting

• HO2S heaters

• instrument cluster

• A/C compressor clutch

• windshield and backlight heaters

• radiator cooling fans

• diagnostics.

ECM

303-118

Engine Management AJ-V8/5HP24

Inputs and Outputs

Inputs and outputs are directed to and from the ECM through hard-wired connections and the CAN and ISO 9141/2 (Serial Communication) data buses contained in the engine management harness (for further information on the data buses, refer to the Technical Guide, XK8 1997 Model Year Introduction).

ECM Pin Connections

Connector/ Pin Circuit Pin Circuit Pin Circuit

EM010

001 Ignition supply 002 Load inhibit 003 Windshield/Backlight heater

request 004 A/C clutch request 005 Ignition supply 006 OK to fuel (where

incorporated) 007 Not used 008 Not used 009 Battery supply 010 Brake switch (foot brake on) 011 Brake switch (cancel cruise

control)

012 ISO 9141/2

(Serial Communication) in (L)

013 ISO 9141/2

(Serial Communication) out (K) 014 Parking brake switch 015 Park/Neutral switch 016 EMS control relay 017 Security acknowledged 018 Not used 019 Not used 020 Sensor ground (ECT, air intake

temperature, accelerator pedal

position, mechanical guard

position and throttle position)

021 Sensor 5 V supply (accelerator

pedal position, mechanical guard position and throttle

position) 022 EGR ground 023 Signal ground 1 024 Not used 025 CAN in (-) 026 CAN in (+) 027 CAN out (-) 028 CAN out (+)

EM011

001 Cruise control set +/set -

(acceleration/deceleration) 002 Not used 003 ECM programming 004 Cruise control on/off 005 Cruise control resume/cancel 006 Engine crank 007 Not used 008 Sensor 5 V supply (accelerator

pedal position, mechanical

guard position and throttle

position)

009 ECT sensor 010 Throttle position sensor 2 011 Throttle position sensor 1 012 Sensor ground (ECT, air intake

temperature, accelerator pedal position, mechanical guard position and throttle position)

013 Mechanical guard position

sensor

014 Shield ground (accelerator

pedal position, mechanical guard position and throttle position sensors)

015 Accelerator pedal position

sensor 2

016 Accelerator pedal position

sensor 1

EM012

001 EGR valve 1 002 EGR valve 2 003 EGR valve 3 004 EGR valve 4 005 A/C high pressure switch 006 A/C low pressure switch 007 Not used 008 Ignition failure amplifier 2

009 Ignition failure amplifier 1 010 A/C clutch relay 011 Not used 012 Air intake temperature sensor 013 MAFS 014 HO2S B 015 HO2S A 016 O2S B (where fitted)

017 O2S A (where fitted) 018 MAFS ground 019 MAFS ground 020 Not used 021 Not used 022 Shield ground (HO2S and O2S)

AJ-V8/5HP24

Engine Management

26 34

ECM PIN CONNECTIONS

Connector/ Pin Circuit Pin Circuit Pin Circuit

EM013

001 Fuel pump control 002 EMS programming 003 Cruise control switch LED 004 ) 005 ) 006 ) 007 ) Not used 008 ) 009 ) 010 ) 011 VSV 3 012 VSV 1

013 VSV 2 014 Throttle motor relay 015 Radiator cooling fans, slow 016 Radiator cooling fans, fast 017 Knock sensor B 018 Knock sensor A 019 Engine speed sensor 020 Camshaft position sensor 021 Not used 022 Ignition coil relay 023 Ignition amplifier 4A 024 Ignition amplifier 3A

025 Ignition amplifier 2A 026 Ignition amplifier 1A 027 Shield ground (knock, engine

speed and camshaft sensors) 028 Engine speed sensor ground 029 Camshaft sensor ground 030 Not used 031 Ignition amplifier 4B 032 Ignition amplifier 3B 033 Ignition amplifier 2B 034 Ignition amplifier 1B

EM014

001 Throttle motor power 002 Throttle motor power 003 Ignition supply 004 Signal ground 2

005 Throttle motor (+) 006 Throttle motor (+) 007 Throttle motor ground 2 008 Throttle motor ground 1

009 Valve timing ground 010 Power ground (miscellaneous) 011 Throttle motor (-) 012 Throttle motor (-)

EM015

001 HO2S B heater 002 HO2S A heater 003 EVAP valve 004 Injector 3B 005 Injector 2B 006 Injector 4A 007 Injector 1A 008 Valve timing solenoid B

009 Valve timing solenoid A 010 Not used 011 Injector ground (1A, 2B, 3B, 4A) 012 HO2S heaters ground 013 Not used 014 Not used 015 Injector 4B 016 Injector 3A

017 Injector 2A 018 Injector 1B

019)

020) Not used

021) 022 Injector ground (1B, 2A, 3A, 4B)

EM014 EM015 EM013 EM012 EM011 EM010

303-129

AJ-V8/5HP24

Engine Management

Engine Harness to Engine Management Harness Pin Connections

Connector/ Pin Circuit Pin Circuit Pin Circuit

PI001

001 Throttle position sensor 2 002 A/C compressor lock sensor

ground 003 Throttle position sensor 1 004 Shield ground (throttle

position sensor) 005 ECT sensor 006 Sensor ground (ECT,

accelerator pedal position,

mechanical guard position and

throttle position) 007 EGR valve 4 008 EGR valve 1 009 EGR valve 2 010 EGR valve 3 011 Generator regulator charge

warning 012 Mechanical guard position

sensor 013 A/C clutch 014 Sensor 5 V supply (accelerator

pedal position, mechanical

guard position and throttle

position) 015 Not used

016 Valve timing solenoid A 017 Knock sensor A 018 Screen ground (knock sensor A) 019 Knock sensor B 020 Shield ground (knock sensor B) 021 Engine speed sensor ground 022 Engine speed sensor 023 Screen ground (engine speed

sensor) 024 Camshaft position sensor ground 025 Camshaft position sensor 026 Shield ground (camshaft

sensor) 027 Valve timing solenoid B 028 Valve timing solenoids and

MAFS/intake air temperature

sensor supply 029 Not used 030 Injector 1A 031 Intake air temperature sensor

ground 032 Injector 2A 033 Injector 3A 034 Injector 4A 035 Injector 1B

036 Injector 2B 037 Injector 3B 038 Injector 4B 039 Ignition coil 4A 040 Ignition coil 1A 041 Ignition coil 3B 042 Ignition coil 2B 043 Ignition coil 4B 044 Ignition coil 3A 045 Ignition coil 2A 046 Ignition coil 1B 047 EGR valve supply 048 Engine oil pressure sensor 049 Shield ground (accelerator

pedal position and mechanical

guard position sensors) 050 Accelerator pedal position 1 051 Accelerator pedal position 2 052 MAFS 053 Ignition supply 054 MAFS ground 055 A/C compressor lock sensor 056 MAFS ground 057 Intake air temperature sensor

ENGINE HARNESS PIN CONNECTIONS

4 10 16 22 26 28

34 40

46 52 57

5 11 17 23 27

31 35

41 47 53

9 13

1 6

PI001

PI002

PI001

PI002

303-061/136/137

AJ-V8/5HP24

Engine Management

Connector/ Pin Circuit Pin Circuit Pin Circuit

PI002

001 ) 002 ) Not used 003 ) 004 ) 005 Injector supply

006 Throttle motor (-) 007 Throttle motor (+) 008 ) 009 ) Not used 010 )

011 Not used 012 Generator regulator supply 013 Not used

CAN Messages

Messages on the CAN data bus used or output by the ECM are detailed below:

Note: This list does not include network monitoring or diagnostic related messages.

Message Used by ECM Source/Used by Message Produced by ECM

ABS MALFUNCTION Brake control module BRAKE PEDAL PRESSED FAST TORQUE REDUCTION CYLINDER ENGINE MALFUNCTION FAST TORQUE REDUCTION IGNITION ENGINE SPEED FRONT LEFT WHEEL SPEED ESTIMATED ENGINE TORQUE FRONT RIGHT WHEEL SPEED PEDAL POSITION REAR LEFT WHEEL SPEED THROTTLE POSITION REAR RIGHT WHEEL SPEED TRACTION ACKNOWLEDGE TORQUE REDUCTION THROTTLE TRACTION STATUS VEHICLE REFERENCE SPEED

FUEL LEVEL Instrument cluster BRAKE PEDAL PRESSED HEADLAMP HIGH BEAM STATUS ENGINE COOLANT TEMPERATURE HEADLAMP LOW BEAM STATUS ENGINE MALFUNCTION SIDE LAMP STATUS ENGINE SPEED

FUEL USED PARK BRAKE STATUS THROTTLE MALFUNCTION AMBER THROTTLE MALFUNCTION RED

GEAR POSITION ACTUAL TCM CRUISE CONTROL STATUS GEAR POSITION SELECTED ENGINE SPEED GEAR SELECTION FAULT ESTIMATED ENGINE TORQUE KICKDOWN STATUS PEDAL POSITION TORQUE CONVERTER SLIP THROTTLE POSITION TORQUE CONVERTER STATUS TORQUE REDUCTION ACKNOWLEDGE TORQUE REDUCTION REQUEST TRANSMISSION INPUT SPEED TRANSMISSION MALFUNCTION TRANSMISSION OIL TEMPERATURE TRANSMISSION OUTPUT SPEED TRANSMISSION OVERLOAD

AJ-V8/5HP24

Engine Management

Sensors

Engine management sensors that input to the ECM are detailed below:

Barometric Pressure Sensor

The barometric pressure sensor is installed in the ECM. It senses ambient pressure in the engine management enclosure of the engine compartment.

HO2S

A HO2S is installed in the intake end of each catalytic converter. They provide inputs proportional to the oxygen content of the exhaust gases leaving the engine. The heater elements improve the response time of the sensors during engine warm-up.

O2S

An O2S is installed in the outlet end of each catalytic converter. They provide inputs proportional to the oxygen content of the exhaust gases leaving the catalytic converter.

Intake Air Temperature Sensor

The intake air temperature sensor is a thermistor integrated into the same housing as the MAFS, in the intake duct immediately downstream of the intake air cleaner. It provides an input inversely proportional to the temperature of the air in the duct.

MAFS

The MAFS is a hot wire sensor that provides an input which is (approximately) proportional to mass air flow into the engine.

OXYGEN SENSORS

303-119

MAFS/INTAKE AIR TEMPERATURE SENSOR

303-128

H02S

02S

AJ-V8/5HP24

Engine Management

Camshaft Position Sensor

The camshaft position sensor is installed in B bank cylinder head at the rear of the intake camshaft. It is a variable reluctance sensor that provides an input of intake camshaft position.

ECT Sensor

The ECT sensor is installed in the coolant outlet duct. It provides an input of coolant temperature at the cylinder head outlets.

Engine Speed Sensor

The engine speed sensor is installed at the rear of the bed plate. It is a variable reluctance sensor that provides an input of engine crankshaft speed and position.

Knock Sensors

The knock sensors are installed in the cylinder block on the inboard side of each cylinder bank. They are piezo-electric sensors that provide inputs to detect and locate detonation during combustion.

ELECTRONIC THROTTLE SENSORS

Accelerator Pedal Position Sensor

The accelerator pedal position sensor is connected to the input shaft in the electronic throttle. It is a dual track potentiometer that provides inputs of driver demand at the accelerator pedal.

Mechanical Guard Position Sensor

The mechanical guard position sensor is a single track potentiometer connected to the mechanical guard in the electronic throttle. It provides an input of the position of the mechanical guard.

Throttle Position Sensor

The throttle position sensor is a dual Hall effect sensor in the motor end of the electronic throttle. It provides inputs of the position of the throttle valve.

Accelerator Pedal Position and Mechanical Guard Position Sensors

Throttle Position Sensor

303-090

AJ-V8/5HP24

Engine Management

ENGINE SENSORS

Knock Sensors

ECT Sensor

Camshaft Position Sensor

Engine Speed Sensor

303-127

AJ-V8/5HP24

Engine Management

ECM Inputs and Outputs

1. Intake Air Temperature Sensor

2. MAFS

3. Throttle Position Sensor

4. (Throttle) dc Motor

5. EGR Valve

6. Fuel Injector

7. Camshaft Position Sensor

8. On-plug Ignition Coil

9. H02S

10. 02S

11. Engine Speed Sensor

12. Accelerator Pedal Position Sensor

13. Mechanical Guard Position Sensor

14. ECT Sensor

15. Knock Sensors

ENGINE MANAGEMENT SCHEMATIC

303-130

AJ-V8/5HP24

Engine Management

Electronic Throttle

The electronic throttle enables the ECM to perform the following functions:

• engine air flow (ie. power) control

• engine idle speed control

• vehicle cruise control

• stability/traction control (in response to ABS commands)

• engine power limiting

• vehicle speed limiting

• reverse gear torque reduction

Engine Air Flow Control

During normal operation, when the accelerator pedal is above idle, the ECM positions the throttle valve in response to the inputs from the accelerator pedal position sensor. The throttle valve follows or leads at a minimum distance the mechanical guard as the guard is moved by the accelerator pedal. Thus engine power output is directly related to driver demand. With the engine running, the time for the throttle to travel from idle to fully open is approximately 120 ms maximum, and from fully open to idle approximately 140 ms maximum.

Idle Speed Control

During engine idle speed control, the ECM operates in a closed speed control loop to maintain a given target idle speed. The ECM uses gear selection, intake air temperature and battery voltage to determine the required target idle speed. Gear selection is derived from the input of the Park/Neutral switch in the transmission rotary switch. Battery voltage is monitored and, if low voltage is detected (11.8 V and below), target idle speeds are increased by up to 50 rpm to increase the output from the generator. When the ECM selects a change of target idle speed, overshoot is kept to 50 rpm maximum.

Certain vehicle services/functions cause a significant change in engine load as they are selected on and off. To minimize the effect on idle speed, the ECM anticipates the change in load rather than correct the subsequent change in rpm. The services/functions the ECM anticipates load changes for are:

• A/C compressor clutch

• gear shifts between Park/Neutral and Reverse/Drive

• headlamps and side lamps

• windshield and backlight heaters

• radiator cooling fans. The ECM detects gear shifts, headlamp status and side lamp status from their related status messages on the CAN data bus. The ECM directly controls the A/C compressor clutch and the radiator cooling fans. The windshield and backlight heaters are controlled by the ACCM upon consent of the ECM via the heater request/load inhibit circuits. If a fault develops in the idle control function, the ECM goes to open loop control. During open loop control, rpm is within +100 and -0 rpm of the target speed for a warm engine (ie. when the coolant temperature is >30 ˚C (86˚F).

Idle Target Speeds Intake Air Temperature, ˚C (˚F) Engine Speed, (rpm)

Drive/Reverse Park/Neutral

>-10 (14) 600 ± 25 650 ± 25

-10 to >-20 (14 to >-4) 625 ± 25 675 ± 25

-20 to >-30 (-4 to >-22) 650 ± 25 700 ± 25 ≤-30 (≤-22) 675 ± 25 725 ± 25

AJ-V8/5HP24

Engine Management

Vehicle Cruise Control

The ECM operates the vehicle cruise control system, in all forward gears, in response to driver inputs through the master, SET+, SET-, CANCEL and RES switches. When the master switch is pressed, two 12 V ignition supplies are connected to the ECM, one direct and one via the brake switch. The LED in the switch comes on to indicate the system is armed. With the system armed, a momentary press of either the SET+ or the SET- switch engages cruise control, provided the vehicle speed is 28 km/h (17.5 mph) or above. The ECM memorizes the current road speed as the `set’ speed and signals the vacuum system to operate the mechanical guard. The inputs from the position sensors in the electronic throttle allow the ECM to monitor and adjust the mechanical guard and the throttle valve to maintain the set speed. The vacuum components are installed in a line connected between the induction elbow and the vacuum actuator on the electronic throttle. In the vacuum system:

• the check valve isolates the system from the induction elbow at wide open throttle when there is little or no vacuum available

• the reservoirs extend the time (to approximately 20 minutes) that, at wide open throttle, sufficient vacuum can be maintained in the system to operate the vacuum actuator

• VSV 1 regulates the vacuum applied to the vacuum actuator to control the position of the mechanical guard

• VSV 2 connects the vacuum actuator to atmosphere to release the mechanical guard when cruise control is disengaged

• VSV 3 is a back-up for VSV 2 (because cruise control disengagement is safety critical)

• filters on the atmospheric ports of VSV 2 and VSV 3 prevent moisture ingress.

CRUISE CONTROL STEERING WHEEL SWITCHES

CRUISE CONTROL MASTER SWITCH

303-131

303-132

AJ-V8/5HP24

Engine Management

CRUISE CONTROL SCHEMATIC

B+ Ignition

Driver’s Facia Fuse Box

To Dimmer Switch

Master Switch

Ignition Switched Ground

Brake Switch

Steering Wheel Switches

Parking Brake Switch

Engine Speed Sensor

-VEHICLE SPEED

-TRACTION STATUS

-GEAR POSITION SELECTED

CAN

ECM

VSV 2

VSV 3

VSV 1

Reservoirs

Check Valve

Throttle Valve Position Sensor

Accelerator Pedal Position and Mechanical Guard Position Sensors

Vacuum Actuator

dc Motor

RES

CANCEL

SET-

SET+

F14

303-133

Brake Cancel Switch

AJ-V8/5HP24

Engine Management

Once cruise control is engaged, a further momentary press of the SET+ or SET- switch increments or decrements the set speed by

1.6 km/h (1.0 mph). The ECM then accelerates or decelerates the vehicle to the new set speed. The ECM stores a maximum of five incremental or decremental commands at any one time. Once the ECM has actioned the first stored command, a further command can be added. On momentary operation of the opposite sense switch, the ECM deletes the last command from memory. Pressing and holding the SET+ or SET- switch causes the ECM to increase or decrease the set speed, and smoothly accelerate or decelerate the vehicle, until the switch is released. To protect against switch failure in the closed position, if either switch is held for longer than 10 minutes, the ECM disables cruise control until the next ignition cycle. The throttle pedal can be used to accelerate the vehicle beyond the set speed, without disengaging cruise control (since the diaphragm actuator is holding the mechanical guard, there is a noticeable reduction in accelerator pedal load up to the point at which the input shaft in the electronic throttle begins to turn the mechanical guard). When the pedal is released the ECM returns the vehicle to the set speed in a controlled manner. Alternatively, a momentary press of the SET+ or SET- switch causes the increased vehicle speed to be adopted as the new set speed. On receipt of an input from the CANCEL switch, the ECM disengages cruise control and clears the set speed from memory. Disengagement is in a controlled manner to provide a smooth return of throttle control to the driver. The ECM disengages cruise control, clears the set speed from memory and immediately

returns control of the throttle to the driver if any of the following occur:

• the master switch is pressed, to switch the

system off

• a fault is detected in the electronic throttle

system, the brake switch or the cruise control switches

• the parking brake is applied

• the engine overspeeds.

The ECM disengages cruise control, immediately returns control of the throttle to the driver and r

etains the set speed in memory, if any of the

following occur:

• the brake pedal is pressed

• the vehicle decelerates too fast (ie. as under heavy braking, to guard against sticking contacts in the brake switch)

• the gear selector moves to neutral, park or reverse

• after resuming cruise control the vehicle accelerates to only 50% of the set speed (eg. due to a steep hill)

• the stability/traction control system operates

• vehicle speed decreases below 26 km/h (16 mph).

On receipt of an input from the RES switch, if a set speed is stored in the ECM memory, the cruise control function is re-engaged and the vehicle accelerated or decelerated to resume the set speed in a controlled manner. The ECM continuously monitors the cruise control switches. If a switch fails closed, on the initial failure the input is treated as a driver command and the system responds accordingly. However, after subsequent disengagement then re-engagement of the system, the input from the failed switch is diagnosed as a fault. On detection of a switch fault, operation of cruise control is inhibited until the fault is corrected. The ECM also conducts internal checking procedures to ensure that only permitted outputs are generated for given input conditions.

AJ-V8/5HP24

Engine Management

CRUISE CONTROL VACUUM SYSTEM

Reservoirs

Check Valve

VSV 1

303-121

Stability/Traction Control

If the CAN- TORQUE REDUCTION THROTTLE message from the brake control module requests torque reduction, the ECM reduces the throttle valve opening. It also changes the CANTRACTION ACKNOWLEDGE message to confirm that torque reduction is in progress.

Engine Power Limiting

If the TCM detects a fault in the transmission, it changes the CAN- TRANSMISSION OVERLOAD message to request an engine torque limit. The ECM then limits throttle valve opening to 18˚ maximum in all forward gears.

Vehicle Speed Limiting

The ECM uses throttle control to limit the vehicle's maximum speed to 248 km/h (155 mph).

Reverse Gear Torque Reduction

When reverse gear is selected the CANTRANSMISSION OVERLOAD message from the TCM requests an engine torque limit. The ECM then limits throttle valve opening to 18˚ maximum.

VSV 2

VSV 3

AJ-V8/5HP24

Engine Management

Fuel Injection

The ECM operates eight injectors to provide the engine with fuel. The amount of fuel required is determined from a base air:fuel ratio which is then adjusted for specific operating conditions. The ECM varies the number and duration of injector pulses per engine cycle to regulate the fuel flow. Injector timing is synchronised with engine rotation, except during starting and acceleration. Feedback signals from the two HO2S in the vehicle's exhaust system enable the ECM to exercise closed loop fueling control and adaptive fueling. Separate channels in the ECM control each bank of injectors. Adaptive fueling accommodates engine efficiency variations, system tolerances and engine ageing. Adaptations are produced at idle speed and four other points through the RPM/load range, on a fully warm engine, when the adaptive fueling function centralizes the feedback range. The ECM retains the adaptations in memory, for use in subsequent driving cycles. If the difference between the new and previous adaptations is excessive, a DTC is logged in the ECM memory. If the battery supply to the ECM is disrupted (eg. battery disconnection), the adaptations are lost from memory. On restoration of the battery supply, engine operation may be uneven until the adaptations are restored, especially at idle speed.

An output from the ECM controls the relay that operates the fuel pump. At ignition on, the pump will operate for 2 seconds without the ignition switch being set to crank, after which time the pump will be de-energized. Similarly, if the engine stops with the ignition on, the pump will be deenergized after 2 seconds. The pump operates continuously while the ignition switch is set to crank, or to on with the engine running.

FUEL PUMP CONTROL

B+ Battery

B+ Ignition

Fuel Pump Relay

Trunk Fuse Box

ECM

Fuel Pump

303-134

Fuel Pump

The two O2S in the vehicle's exhaust system provide inputs which enable the ECM to monitor the efficiency of the downpipe catalytic converters. These inputs also enable the ECM to modify the HO2S inputs, to optimise the life of the catalytic converters.

Base Fuel Map

The ECM contains a base fuel map that corrects the base air:fuel ratio to the optimum mixture for a nominal engine throughout the engine speed and load ranges.

Battery Voltage Correction

Fuel flow through the injectors changes with voltage, so the ECM monitors their supply voltage and compensates for any variation from the nominal.

AJ-V8/5HP24

Engine Management

Starting

The fueling start strategy operates independent of accelerator pedal position or movement, with the exception of a wide open throttle. The ECM produces steady state running at the target idle speed within 2 seconds of firing, after an overshoot of 200 to 300 RPM maximum. If the accelerator pedal demands a wide open throttle during cranking, the ECM disables fuel injection (and signals the throttle valve to the fully open position) to clear the fuel vapor from a "flooded" engine.

Warm-up Enrichment

During engine warm-up, the ECM determines the fuel required from maps which modify an enrichment factor for coolant temperature, engine speed and load.

Transient Fueling

During acceleration and deceleration, the ECM adjusts fueling to optimise the air:fuel ratio for exhaust emission, response and economy. This function operates over the full temperature range for all acceleration and deceleration rates.

Full Load Enrichment

At full load, the ECM inhibits closed loop fueling and increases the fuel supply to enrich the air:fuel ratio. Full load is derived from throttle valve position and engine speed. The degree of enrichment is dependent on engine speed.

Engine Overspeed Protection

The ECM disables fuel injection if engine speed reaches 7100 RPM. Fuel injection is re-instated when RPM falls to 7050.

Stability/Traction Control

If the CAN-FAST TORQUE REDUCTION CYLINDER message from the BCM requests fuel intervention, the ECM reduces engine torque by disabling fuel injection until the throttle valve reaches its required torque reduction position. It also changes the CAN-TRACTION ACKNOWLEDGE message to confirm that torque reduction is in progress.

Ignition

The ECM supplies two ignition amplifier modules, which each supply four spark plug mounted ignition coils. The ECM varies the ignition timing to optimise power, emissions and driveability at all operating conditions. A diagnostic signal from each amplifier module enables the ECM to monitor the supply to each ignition coil. If the ECM detects a failure it disables fuel injection to the affected cylinder.

IGNITION AMPLIFIER MODULES

303-091

Over-run Fuel Cut-off

When the throttle is closed at high engine speeds, the ECM disables fuel injection until the engine is at a lower speed. The speeds at which fuel injection is disabled and re-instated are mapped against coolant temperature. On re-instatement the ECM uses a lean air:fuel ratio, to provide a smooth transition between the two states, which it then progressively returns to the nominal. The initial injector pulses are given a correction value to compensate for cylinder wall wetting. The ECM derives the air:fuel ratio for reinstatement from throttle valve position and engine speed. During over-run fuel cut-off, operation of the EVAP valve, EGR valve (where fitted) and closed loop fueling are inhibited.

AJ-V8/5HP24

Engine Management

Base Ignition Map

A base ignition map contains optimum timing for a nominal engine throughout the engine speed and load ranges. Corrections are then added to adjust for specific operating conditions.

Temperature Corrections

Corrections are added to the ignition timing to compensate for variations in intake air temperature and engine coolant temperature.

Knock Control

Between 700 and 6800 RPM, the ECM retards the ignition timing of individual cylinders if it detects detonation. Also, during acceleration at critical load and speed conditions, the ECM retards the ignition timing to prevent the onset of detonation.

Full Load Advance

At full load, the ECM advances the ignition timing at the same time as fuel enrichment is applied. The degree of advancement is dependent on engine speed.

Fuel Cut-off Interaction

Immediately prior to over-run fuel cut-off, the ECM retards the ignition timing to provide a smooth transition between the two states. On fueling re-instatement the ECM progressively returns the ignition timing to the nominal. Throttle valve position and engine speed determine the rate at which the timing is returned to the nominal.

Starting

The ECM incorporates separate timing values for starting.

EGR

The ignition timing is advanced while the EGR system is active. The degree of advancement is dependent on engine speed and load.

Gear Shift Management

When the TCM decides a gear shift is necessary, it requests a percentage torque reduction using the CAN - TORQUE REDUCTION REQUEST message. The ECM then retards the ignition timing sufficient to achieve the torque reduction requested. As the ECM retards the ignition, it

changes the CAN-TORQUE REDUCTION ACKNOWLEDGE message to the TCM to trigger the gear shift.

Transient Interaction

A correction is applied to the ignition timing during throttle transients. The correction is against rate of change for both opening and closing of the throttle.

Stability/Traction Control

If the CAN-FAST TORQUE REDUCTION IGNITION message from the BCM requests ignition intervention, the ECM retards the ignition by the amount requested until the throttle valve reaches its required torque reduction position. It also changes the CAN-TRACTION ACKNOWLEDGE message to confirm that torque reduction is in progress.

EVAP System

The ECM operates the EVAP valve to purge the fuel vapor from the carbon canister. Purge rates (ie. the amount the EVAP valve opens) are a function of engine operating conditions and the vapor concentration level. The engine operating conditions that affect the purge rate are:

• speed and load

• coolant temperature

• time from start-up

• closed loop fueling. To determine the vapor concentration level, the ECM applies stepped opening signals to the EVAP valve and monitors the subsequent fueling correction. This is usually performed prior to purging, so that when purging starts, the EVAP valve can immediately be set to the optimum position. If the ECM is unable to determine the vapor concentration before purging, it uses a default value which it then modifies while purging is in progress. During purging, the ECM applies a correction to the basic fueling calculation based on the vapor concentration level. Purging is inhibited during fuel cut-off and stability/traction control fueling intervention.

AJ-V8/5HP24

Engine Management

Variable Valve Timing

The ECM energizes the valve timing solenoids to advance the intake valve timing and de-energizes them to retard it. The ECM uses engine load and speed maps to decide when to advance and retard the timing. The maps incorporate hysteresis for both engine load and speed to prevent "hunting". Between 1250 and 4500 RPM (nominal), at engine loads greater than approximately 25 % of the maximum, the timing is advanced. At low engine loads and at the two ends of the RPM range, the timing is retarded. System operation is inhibited at engine coolant temperatures below -10˚C (14˚F). System operation is monitored using the input from the camshaft position sensor. If a fault is detected the ECM defaults to the retarded (de-energized) condition.

EGR System

The ECM operates the 4 pole stepper motor in the EGR valve to control the recirculation of exhaust gases. Unlike previous systems, there are no temperature or position feedback signals from the valve. The ECM monitors EGR operation using changes of mass air flow.

Engine Starting

At ignition on, if the gear selector is in Park or Neutral, the ECM enables the fuel injection and ignition functions. It also outputs a hard wired digital security acknowledge signal to the BPM to enable engine cranking. While the engine cranks, the BPM outputs a hard wired digital engine cranking signal to the ECM, which employs engine starting strategies for the duration of the signal. If the gear selector is not in Park or Neutral at ignition on, the ECM inhibits the fuel injection and ignition functions, and withholds the security acknowledge signal to prevent cranking.

VARIABLE VALVE TIMING MAP

Engine Speed, RPM x 1000

Retarded Advanced

Engine Load

2 3 4 5 6 7

303-135

AJ-V8/5HP24

Engine Management

H02S Heaters

The ECM energizes the heater elements of the HO2S during engine warm-up to shorten the time it takes for them to produce accurate outputs.

Instrument Cluster

The instrument cluster uses CAN messages from the ECM to operate the trip computer, tachometer, engine coolant temperature gauge and the BRAKE, CHECK ENG and general warning lamps.

Note: The CHECK ENG lamp is commonly

known as the MIL.

A/C Compressor Clutch

Operation of the A/C compressor clutch is controlled by the ECM, to prevent unnecessary loads on the engine during unfavorable operating conditions. On receipt of an A/C request signal from the A/CCM, the ECM immediately energizes the A/C compressor clutch relay provided the engine is not at idle speed, the coolant temperature is not above 119˚C (246˚F) and the throttle valve is not fully open. When the A/C compressor clutch relay energizes, the relay output is sensed by the A/CCM, confirming that the A/C compressor clutch is engaged. If the engine is at idle speed, the coolant temperature is above 119˚C (246˚F) or the throttle is fully open, the ECM outputs a load inhibit signal to the A/CCM and delays energising the A/C compressor clutch relay. At idle speed the delay is only momentary (in the order of 50 ms) while idle speed compensation is implemented, after which the load inhibit signal is removed. At coolant temperatures above 119˚C (246˚F) or with a fully open throttle, the delay is for the duration of the inhibiting condition. Similarly, with the A/C compressor clutch relay already energized, if the engine coolant temperature exceeds 119˚C (246˚F) or the throttle goes to fully open, the ECM de-energizes the A/C compressor clutch relay and outputs the load inhibit signal to the A/CCM until the inhibiting condition is removed.

When the windshield heaters and/or the backlight heater are requested on, the A/CCM sends a screen request signal to the ECM. Provided the engine is not at idle speed, the coolant temperature is not above 119˚C (246˚F) and the throttle valve is not fully open, the ECM takes no action and the A/C control module subsequently energizes the heaters. If the engine is at idle speed, the coolant temperature is above 119˚C (246˚F) or the throttle is fully open, the ECM outputs the load inhibit signal (the same one as used for the A/C compressor clutch operation) to the A/CCM to delay energising the heaters. At idle speed the delay is only momentary while idle speed compensation is implemented, after which the load inhibit signal is removed. At coolant temperatures above 119˚C (246˚F) or with a fully open throttle, the delay is for the duration of the inhibiting condition. Similarly, with the heaters already energized, if the engine coolant temperature exceeds 119˚C (246˚F) or the throttle goes to fully open, the ECM outputs the load inhibit signal to the A/CCM and the heaters are de-energized until the inhibiting condition is removed.

Radiator Cooling Fans

The ECM monitors inputs from the A/C single and triple pressure switches, and from the ECT sensor on the engine, to control the operation of the two radiator cooling fans. Outputs from the ECM control two relays contained in the radiator fans module, to operate the fans in off, slow or fast mode. In the slow mode the fans are connected in series; in the fast mode the fans are connected in parallel. Hysteresis in the temperature and pressure switching values prevents "hunting" between modes.

Windshield and Backlight Heaters

AJ-V8/5HP24

Engine Management

To counteract the increase in engine coolant temperature that occurs after the engine stops, at ignition off:

• if the fans are already on, the ECM keeps them on for 5 minutes, or until the ECT decreases to a pre-determined value, whichever occurs first

• if the fans are off, the ECM determines, from ECT and intake air temperature inputs, if the fans need to be switched on. If they do, it switches them on for 5 minutes, or until the ECT decreases to a pre-determined value, whichever occurs first.

Radiator Fan Switching Points

Mode Coolant Temperature, ˚C (˚F) A/C System Pressure, Bar (psi)

On Off On Off

Slow 90 (194) 86 (187) 12 (174) 8 (116) Fast 97.5 (207.5) 93.5 (200.5) 22 (319) 17.5 (254)

Diagnostics

The ECM performs self test routines and monitors engine functions, inputs and outputs to ensure correct operation of the engine and the engine management system. Hard wired inputs and outputs are monitored for short and open circuits, and sensor inputs are also monitored for range. Additional checks are run on the more critical sensor inputs to ensure their validity. Some of the more critical inputs have substitute or default values which the ECM adopts if the input is diagnosed as faulty. Any faults detected are logged in the ECM memory as DTC. The ECM also outputs engine malfunction messages on the CAN and adopts a default mode of operation. Most default modes retain some degree of engine operation (limp home). The ECM also stores OBD II related DTC detected by other control modules on the CAN. Non-OBD II related DTC are retained in the memory of the control module that detects the fault.

To prevent false DTC being logged, the monitoring of some inputs and engine functions is inhibited while the vehicle is above a given altitude:

• at altitudes of 2438m (8000ft) and above,the ECM inhibits diagnostics on: EGR valve and EGR flow; EVAP valve and EVAP purge flow; idle speed control; misfire detection; catalytic converter efficiency.

• at altitudes of 2652m (8700ft) and above, the ECM also inhibits diagnostics on: HO2S; MAFS; O2S.

AJ-V8/5HP24

Engine Management

Additional Input Checks

Input Additional Strategy Action, Substitute or DefaultValue

Accelerator pedal Accelerator pedal position input 1 compared to If one input fails, the input of the other position (x 2) and accelerator pedal position input 2. two is used. mechanical guard Both accelerator pedal position inputs compared to If two inputs fail, ECM adopts fixed position mechanical guard position input. throttle mode.

Throttle position 1 compared to input 2. If either input fails, ECM adopts (x 2) Input 1 compared to target value (target value mechanical guard mode of operation.

depends on operating mode, eg. normal running, cruise control, traction active).

Engine coolant After engine start, checks that expected If fault detected, uses substitute value temperature temperature increase occurs, then monitors for derived from transmission oil

excessive temperature decrease. temperature.

Mass air flow Compares input with predicted air flow (derived If fault detected, uses throttle angle as

from a map of throttle angle against engine speed). load measurement.

Intake air Monitors for too fast change of input and for fixed If fault detected, uses a fixed intake air temperature input. temperature of 50˚C (122˚F).

Default Modes

Mode Effect General CHECK Message

Warning ENG Lamp Lamp (MIL)

Engine shutdown Activates fuel cut-off to stop engine Red On ENGINE FAULT Fixed throttle Fixed throttle valve angle of approximately 2.5˚ Red On ENGINE FAULT

set, producing maximum engine speed (unloaded) of approximately 1200 RPM.

Mechanical guard Engine speed increases as throttle valve goes to Red On ENGINE FAULT

mechanical guard position; idle speed increases to approximately 1400 RPM; full throttle available

Engine speed Engine speed limited to 3000 RPM Amber On ENGINE FAULT limiting

Redundancy Substitute or default value adopted; no noticeable Amber Off ENGINE FAULT

difference in performance

Exhaust emission Substitute or default value adopted; potential None On None

difference in performance

Note: In mechanical guard mode, fuel intervention smooths the transition from normal to default mode, to prevent sudden

acceleration of the vehicle. Also, fuel intervention limits idle speed. Without fuel intervention idle speed would be approximately 2000 RPM and cause excessive shock loads on the transmission when shifting out of Park or Neutral. When engine load increases, idle speed fuel intervention is progressively withdrawn.

AJ-V8/5HP24

Transmission

Introduction

The new ZF 5HP24 automatic transmission system features five forward gears and one reverse gear. It also features a filled-for-life oil system. Gearshift management is achieved using a Transmission Control Module (TCM).

TRANSMISSION

Rotary Switch Connector

Rotary Switch and Oil Inlet Pipe

Oil Outlet Pipe and Selector Cable

Level/Filler Plug

307-012

AJ-V8/5HP24

Transmission

Tecnical Data

Transmission weight including fluid and torque converter 95.8 kg (211 lbs) Oil Type ATF Esso LT71141 Oil Capacity 10 liters (2.645 US. gals) Gear Ratios 1st Gear 3.571:1

2nd Gear 2.202:1 3rd Gear 1.505:1 4th Gear 1.000:1 5th Gear 0.803:1 Reverse 4.095:1

Gearshifting

Driver gear selection is transmitted from the gear selector lever by cable to a lever fitted to a selector shaft in the transmission casing. This shaft moves the manual valve and the rotary switch. The rotary switch signals all gear positions except D to 4. A separate switch in the driver gear selector mechanism detects movement of the selector between D and 4. The communication of driver gear selection to the TCM is made by the rotary switch. Gear shift points are selected by the TCM in response to output speed, engine load, selector position, accelerator pedal position and driver mode selection. Driver control of the shifting is via the selector lever, throttle pedal position, kickdown switch and mode switch. Two shift modes are available, sport and normal, controlled by the driver from a switch on the gear selector surround. During kickdown, gear upshifts occur at 6800 RPM engine speed.

Mechanical Description

The unit is an oil filled-for-life system therefore no dipstick is fitted to the transmission. A filling/level plug is located at the right-hand side rear of the casing for service oil level checking and replenishment, if required. To achieve effective cooling, the oil is pumped from the transmission casing at the front left-hand side of the casing to the car mounted oil cooler. The oil is returned from the cooler to the inlet connection on the front right-hand side of the casing. The cooler is a plate-type design made from aluminum and is located in the car radiator outlet tank. To detect changes in oil viscosity which occur as the oil temperature changes, an oil temperature sensor is located in the unit casing sump. Also located

in the transmission casing are the input shaft speed sensor (turbine speed) and output shaft speed sensor (vehicle speed). The torque converter is a lightweight unit which, because of its low mass, improves engine responsiveness. The torque converter bell housing is bolted to the transmission casing. Mounting of the transmission is conventional by bolting the torque converter bell housing to the engine. The rear extension housing is bolted to the transmission casing and forms the rear engine/transmission mounting point. It also carries the output shaft oil seal. The electro-hydraulic module contains three solenoid valves and five pressure regulators for gear shifting. Each of the three solenoid valves control the flow of transmission fluid to the selected clutches. One pressure regulator serves as master pressure control for the entire system and one is used exclusively for torque converter clutch lock-up operation. Replacement transmission units are shipped complete with the torque converter and housing, extension housing, coupling flange and rotary position switch. They are also fully filled with 10 liters (2.645 US. gals) of oil. Consequently, when undertaking a transmission replacement, oil replenishment should not be necessary. The exterior of the transmission is coated with a nondrip corrosion protection oil, which must not be

AJ-V8/5HP24

Transmission

Electrical Description

EM046

BLACK

mistaken for an oil leak.

Electrical Connections

Bayonet Connector

A round, 16-pin, bayonet electrical connector is fitted at the rear left-hand side of the transmission which communicates with the 5 pressure regulators, 3 shift solenoids, oil temperature sensor and the input and output

Connector/ Pin Circuit Pin Circuit Pin Circuit

shaft speed sensors.

EM046

001 Output Speed Sensor (+) 002 Pressure Regulator 1 003 Pressure Regulator 2 004 Shift Solenoid Valve 3 005 Turbine Speed Sensor (+)

006 Turbine Speed Sensor (-) 007 Pressure Regulator 3 008 Shift Solenoid 1 009 Shift Solenoid 2 010 Output Speed Sensor (-) 011 Pressure Regulator 4

012 Solenoid Valves (+) 013 Analog Ground 014 Oil Temperature Sensor 015 Pressure Regulator 5 016 Regulator (+)

Rotary Switch Connector

The rotary switch, mounted on the right-hand side of the casing, has a spline arrangement which prevents misalignment with the selector shaft. A locating pin and two bolts secure the rotary switch to the transmission casing. This locates the switch with the transmission casing and the shaft in one place only. The switch requires no other setting up procedure. A 10-way connector with flying lead connects the rotary switch to the engine management harness. The connector is retained on a multiconnector bracket bolted to the transmission casing/torque converter housing joint.

BLACK

EM047

SOCKET

Connector/ Pin Circuit Pin Circuit Pin Circuit

EMO47

00A Position L1 00B Position L2 00C Position L3 00D Position L4

00E Digital Ground 00F Not Used 00G Not Used 00H Not Used

00J 12V Power Supply 00K Park & Neutral Switch

EM 046

BAYONET CONNECTOR

EM 047

ROTARY SWITCH CONNECTOR

307-024

307-023

AJ-V8/5HP24

Transmission Management

The transmission management system uses both analogue and digital signals, to control the operation of the transmission. Digital signals are processed by the TCM to and from the vehicle multiplex network. Other input/output analogue signals are hardwired to the TCM. This information is used primarily by the TCM to decide which shift program to implement, which gear to select and for shift energy management. If a fault occurs, the TCM will take default action and inform the driver via the Message Centre and amber warning light.

Harness Connector

The vehicle harness connector for the TCM is an 88-way latching connector. The TCM is wired to the electrical pressure regulators/solenoids, oil temperature sensor and shaft speed sensors in the transmission casing.

Sport Mode

When sport mode is selected by the driver using the mode switch, the sport pattern is only activated when a set cornering force is achieved, or the kickdown switch is pressed. The vehicle speed and the difference in speeds between the two front wheels is used to calculate the amount of cornering force.

Torque Convertor Lock-up

The torque convertor lock-up clutch is engaged as a function of throttle position, output speed, oil temperature, gear shift and shift program. Lockup is possible in 2nd, 3rd, 4th and 5th gears but is usually restricted to 4th and 5th gears. During a gear shift the TCM controls the amount of slip of the lock-up clutch to enhance shift quality.

Oil Temperature

When the engine coolant or transmission oil temperature exceeds set thresholds a hot mode program is selected which locks the torque convertor clutch, minimising the amount of heat entering the engine cooling system from the transmission oil.

TCM

303-009

AJ-V8/5HP24

Transmission Management

Gear Shift Interlock

Gear shift interlock is controlled by the BPM, part of the SCP network. The gearshift release will only be activated when the ignition is in position II, transmission is in Park and the brake pedal is depressed. Once transmission is out of Park, the brake pedal has no effect on gearshifting and the interlock is disabled.

Reverse Inhibit

Selection of reverse with the vehicle moving forwards above walking pace is electrically inhibited, unless the vehicle is in the default "limp-home" mode.

Kickdown

A floor mounted switch/pedal position sensor signals the TCM to select the lowest gear to give maximum torque for acceleration.

Torque Control

The TCM synchronises the operation of the transmission clutches and invokes shift energy management to control engine output torque during a gear shift (Refer to EMS, page 60).

Traction Mode

The traction program compliments the traction control system and is implemented whenever traction control intervenes to maximize wheel stability.

Cruise Mode

Cruise mode reduces unwanted hunting of the transmission gearshifting and is activated when cruise control is resumed and when the vehicle is cruising near the set speed.

Gradient Mode

The gradient program enhances vehicle performance, driveability and cooling when the vehicle is climbing a gradient.

Start Inhibit

The rotary switch also provides the start inhibit function to the ECM, which will not allow an engine start until the gear selector is in either Park or Neutral.

Fault Monitoring/Diagnostics

The TCM constantly monitors the transmission system for faults. In the event of a fault occurring, the transmission is protected by a limp home mode. This mode allows use of P, R, N, and 4. It also signals the ECM to switch on the CHECK ENG (MIL) lamp. The TCM is able to diagnose faults in components which affect exhaust emissions. Communication with the PDU is through the J1962 connector which allows accurate diagnosis of transmission problems. Additional diagnostic functions facilitate fast repair of faults. All transmission OBDII information is stored for future data analysis in the ECM.

AJ-V8/5HP24

Transmission Management

Transmission Control Module Pin Connections

Connector/ Pin Circuit Pin Circuit Pin Circuit

EM007

001 Pressure Regulator 2 002 Mode Switch Illumination 003 Not used 004 Pressure Regulator 4 005 Pressure Regulator 1 006 Power Ground 007 Not used 008 Position Switch L2 009 Position Switch L4 010 Not used 011 Not used 012 Mode Switch Pin B 013 Drive to Fourth Switch 014 Turbine Speed (-) 015 Shield (Output Speed Sensor) 016 Output Speed (+) 017 Not used 018 Kickdown Switch 019 Not used 020 Not used 021 Analogue Ground 022 Oil Temp Sensor

023 Shield (Input Speed Sensor) 024 Not used 025 Not used 026 Battery Feed 027 Not used 028 Digital Ground 029 Pressure Regulator 3 030 Shift Solenoid 1 031 Not used 032 Shift Solenoid 3 033 Shift Solenoid 2 034 Power Ground 035 Not used 036 Position Switch L1 037 Position Switch L3 038 ) 039 Not used 040 ) 041 ) 042 Turbine Speed (+) 043 Not used 044 Output Speed (-)

045 Mode Switch Pin A 046 ) 047 Not used 048 ) 049 ) 050 ) 051 Pressure Regulator 5 052 Solenoid valve + ve 053 Pressure regulator + ve 054 Fused Ignition + ve 055 Fused Ignition + ve 056 to 081 Not used 082 CAN Link In - ve 083 CAN Link In + ve 084 CAN Link Screen 085 CAN Link Out - ve 086 CAN Link Out + ve 087 Not used 088 Not used

T.C.M

BLACK

TCM

EM 007

307-022

AJ-V8/5HP24

Transmission Management

TRACTION STATUS Brake Control Module TRANSMISSION INPUT SPEED ABS STATUS TRANSMISSION OUTPUT SPEED FRONT LEFT WHEEL SPEED TORQUE CONVERTER SLIP FRONT RIGHT WHEEL SPEED KICKDOWN SWITCH

GEAR POSITION ACTUAL TORQUE CONVERTER STATUS TRANSMISSION SHIFT MAP TRANSMISSION MALFUNCTION TRANSMISSION FAULT CODES

Instrument Cluster GEAR POSITION ACTUAL

GEAR POSITION SELECTED TRANSMISSION OIL TEMPERATURE TRANSMISSION MALFUNCTION

ESTIMATED ENGINE TORQUE ECM TORQUE REDUCTION REQUEST THROTTLE VALVE POSITION TRANSMISSION OVERLOAD ACCELERATOR PEDAL POSITION TRANSMISSION INPUT SPEED TORQUE REDUCTION TRANSMISSION OUTPUT SPEED ACKNOWLEDGE TORQUE CONVERTER SLIP ENGINE SPEED KICKDOWN SWITCH CRUISE STATUS GEAR POSITION ACTUAL BRAKE PEDAL DEPRESSED TORQUE CONVERTER STATUS ENGINE COOLANT TEMPERATURE GEAR POSITION SELECTED ENGINE MALFUNCTION TRANSMISSION SHIFT MAP

TRANSMISSION OIL TEMPERATURE TRANSMISSION MALFUNCTION TRANSMISSION FAULT CODES

Can Messages

Messages on the CAN data bus used or output by the TCM are detailed below:

Note: This list does not include network monitoring or diagnostic related messages.

Message Used by TCM Source/Used by Message Produced by TCM

AJ-V8/5HP24

Service Tools

New Tools

The table below lists the new service tools required for the AJ V8 engine. These are in addition to the tools already in use on 6 and 12 cylinder engines, some of which can also be used on the AJ V8. Details of new service tools for the 5HP24 transmission will be supplied at a later date.

Part Number Description

JD 215 Camshaft setting/locking tool JD 216 Crankshaft setting/locking peg JD 217 Timing chain tensioner tool JD 218 Timing chain wedges (2 each) JD 220 Dummy main bearing caps (5 each) JD 221 Bore protector - connecting rod installation (2 each) JD 222 Engine rear lifting brackets (1 pair) JD 223 Engine stand mounting brackets (1 pair) JD 229 Crankshaft rear oil seal remover/replacer JD 230 Belt tensioner release tool JD 231 Fuel injector remover JD 232 Valve lifter hold-down tool JD 233 Fan nozzle air gun JD 234 Crankshaft front oil seal remover JD 235 Crankshaft front oil seal replacer MS 76-140-5 Valve seat 5 mm pilot (for use with existing MS 76 valve seat cutter tools) 18G 1437-2 Adapter (for use with existing front pulley lock tool 18G 1437)

- Cranked 13 mm box wrench, for starter motor upper securing bolt (eg. Snap-on part number CXM 1113)

- Spring band hose clamp pliers (eg. Snap-on part number HCP 20)

- Torque/Angle disc, for yield tightening of bolts (eg. Snap-on part number TA 360)

- Valve seal pliers (eg. Snap-on part number YA 8230)

- 24 mm, 0.375 inch drive, open wrench, for knock sensors (eg. Snap-on part number FCOM 24)

- 8 inch long, 0.375inch drive, angle extension, for use with 24 mm open wrench

(eg. Snap-on part number FXW 8)

Jaguar AJ-V8 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual