OTHER Self Study Program 153 – 1.9L TDI Industrial Engine ssp-153-19l-tdi-ve-pump

1,9 ltr-TDI-Industrial Engine

Technical Status: 4/1999

Contents

· Combustion process . . . . . . . . . . . . . . . .3

· Injectors . . . . . . . . . . . . . . . . . . . . . . . . .4

· Needle Lift Sender . . . . . . . . . . . . . . . . .5

· Air-mass Flow Meter . . . . . . . . . . . . . . .6

· Modulating piston movement sender . .7

· Installation position . . . . . . . . . . . . . . . .8

· System overview . . . . . . . . . . . . . . . . .10

· Fuel regulation . . . . . . . . . . . . . . . . . . .12

· Injection commencement control . . . . .17

· Exhaust gas recirculation . . . . . . . . . . .22

· Charge pressure control . . . . . . . . . . .24

· Glow plug system . . . . . . . . . . . . . . . .26

· Emission characteristics . . . . . . . . . . . .27

· Internal functions in the control unit . .29

· Self-diagnosis . . . . . . . . . . . . . . . . . . .30

· Performance diagram . . . . . . . . . . . . .31

· Specifications . . . . . . . . . . . . . . . . . . . .32

Detailed instructions regarding testing, adjustment and repair can be found in

the Workshop Manual "Volkswagen Industrial Engine".

2

Combustion process

In the direct injection engine, diesel fuel is injected directly into the main combustion
chamber. This results in more efficient combustion and lower consumption.

The intake port, pistons and injectors have been designed specifically to optimise
the combustion process with respect to noise emission and running characteristics.

Inlet swirl port

The intake port is shaped in such a way that it
induces a swirling movement of the intake air
and, as a result, produces greater turbulence
in the combustion chamber and piston recess.

Piston recess

The shape of the piston recess has been opti­mised specially for this engine.

5-hole injector

The fuel is injected into the piston recess in
two stages and is ignited by the hot air.
The two-stage injection process avoids a sharp
pressure rise.

3

Injector needle

Two-spring injector holder

To minimise the combustion noise level in the diesel engine and keep mechanical
load low, it is necessary for the pressure to rise gently in the combustion chamber.
In the case of chamber-type diesel engines, this gentle rise in pressure is achieved,
first, by injecting fuel into the pre-chamber or the swirl chamber and, secondly, by
using pintle-type injectors. Also, the fuel should be injected gradually, not all at once.

A two-spring injector holder has been developed for the 1.9-ltr. direct injection
engine. This injector holder, a key factor contributing to the engine's "soft" combus­tion characteristic, allows fuel to be injected in two stages.

The injector is designed as a five-hole nozzle.

Spring 1

Spring 2

This pre-injection cycle produces a gentle rise in the combustion pressure
and creates the conditions for igniting the main fuel quantity.

As the injection pump delivers more fuel than can actually flow through

Injector needle

the small gap, the pressure in the injector rises. The force of the second
spring is overcome, and the injector needle is lifted further. The main
injection cycle now follows at a higher injection pressure.

Stroke 1

Stroke 1+2

Stroke 2

Function

Two springs with different
thicknesses are integrated

in the injector holder.
The springs have been
adapted in such a way
that the injector needle is
only lifted against the
force of the first spring
when injection starts.
A small quantity of fuel is
pre-injected through the
small gap which appears
at low pressure.

4

Needle Lift Sender

The injector of the 3rd cylinder is equipped with a needle lift sender (G80) for regis­tering the point of commencement of injection.
The sender signals the actual opening time of the injector to the control unit. This
signal provides the control unit with feedback on whether the point of commence­ment of fuel injection conforms to the map.

Injector holder

Function

Needle lift sender G80 is a
solenoid and is supplied with a
constant current by the control
unit. This produces a magnetic

Solenoid

field.

A pressure pin inside the sole­noid forms an extension to the
end of the injector needle. The
movement of the injector nee­dle alters the magnetic field
and causes distortion of the
DC voltage applied to the sole­noid.

Pressure pin

Substitute function

If the needle lift sender fails, an emergency running program is started. In this pro­gram, the commencement of fuel injection is controlled according to fixed setpoints
as defined in a map. The injection quantity reduced in addition.

The control unit calculates the
actual point of commencement
of fuel injection from the time
difference between the needle
lift pulse and the TDC signal
supplied by the engine speed
sender. At the same time, the
system compares the actual
point of commencement of
injection with the setpoint
stored in the control unit and
corrects any deviations from

the setpoint.

5

Air-mass flow meter

The task of the air-mass flow meter is to measure the fresh air mass supplied to the
engine.
This fresh air mass is used to calculate the exhaust gas recirculation rate and the
permissible injection quantity.

Air-mass flow meter

Hot film

Function

A heated surface, the hot film, is regulated to a constant temperature.
The intake air cools the hot film as it flows past.
The current serves as a measure of the intake air mass necessary to keep the tem­perature of the hot film constant.

Substitute function

If the air-mass flow meter fails, the control unit defaults a fixed air mass value.
This fixed value is calculated such that a reduction in engine performance can only
occur in the part-throttle range.

Advantages of hot-film air mass metering

 Air-mass data can be acquired without additional air pressure and temperature

sensors
 Reduced flow resistance compared to sensor flap air-flow metering
 It is no longer necessary to burn off the hot wire as in the hot wire air-mass flow

meter.

6

Modulating Piston Movement Sender

Modulating piston movement sender G149 supplies the control unit with information
on the momentary position of the quantity adjuster in the injection pump.
The injected fuel quantity is calculated from this information.

Sender G149 is a non-contact sensor for measuring the angle of rotation.
It is attached to the eccentric shaft of the quantity adjuster.

Distributor injection pump

Coil with AC voltage

Iron core

Movable metal ring

Fuel temperature
sensor G81

Eccentric shaft

Stationary metal ring

Function

An alternating magnetic field is produced in a specially shaped iron core by AC volt­age. A metal ring attached to the eccentric shaft moves along the iron core and influ­ences this magnetic field. The change in the magnetic field is evaluated electronical­ly in the control unit and indicates the position of the quantity adjuster.

Substitute function

If the control unit does not receive a signal from the sender for modulating piston
movement, the engine is turned off for safety reasons.

The new non-contact sender offers the following advantages:
 High wear resistance
 High interference immunity
 Low susceptibility to temperature fluctuation

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7

Air-mass flow meter

Exhaust gas recirculation
valve N18

Solenoid valve for charge
pressure control N75

EGR valve

Hose connection

Intake manifold pressure sender

E

Air-mass flow meter G70

needle lift sender G80

Distributor injection pump

Injector with

Coolant temperature sender G6

8

Intake manifold temperature
sensor G72

Engine speed sender G28

9

System overview

To optimise engine performance with respect to torque delivery, consumption and
emission in every operating situation, the EDC control unit refers to 25 maps and
characteristic curves.
Sensors supply the control unit with information regarding the vehicle's momentary
operating state.

Sensors

Needle lift sender G80

Engine speed sender G28

Air-mass flow meter G70

Coolant temperature sender G62

Intake manifold temperature sensor G72

Clutch pedal switch F36

Brake switch F

Brake pedal switch F47

EDC control unit J248

Intake manifold
pressure sender

Accelerator position sender G79

Modulating piston
movement sensor G149

Fuel temperature sen­der G81

Auxiliary signals

Diagnostic connector

Note:
The self-diagnosis
monitors all the com­ponents above.

10

After the information supplied by the sensors has been evaluated, the control unit
sends signaIs to the final control elements (actuators). Injection quantity, com­mencement of injection, charge pressure and exhaust gas recirculation are moni­tored and regulated in this way.
The EDC control unit also assumes the tasks of controlling the glow plug system,
the auxiliary heater and the cruise control system.

Actuators

Glow plug warning lamp
Fault warning lamp K29

Exhaust gas recirculation valve N18

Solenoid valve for charge pressure
control N75

quantity adjuster N146

Fuel cut off valve N109

Commencement of injection valve N108

Auxiliary signals

SSP 153/11

11

Fuel regulation

The 1.9-ltr. TDI engine meters the fuel quantity electronically.
The correct quantity is determined in the EDC control unit using the sensor informa­tion as detailed below, and a signal is sent to the quantity adjuster N146 in the injec­tion pump. There is no mechanical link between the accelerator pedal and the injec­tion pump.

To avoid black exhaust, the injection quantity is limited via a smoke characteristic
curve in order to avoid black smoke.

Overview

Accelerator position sender G79

Coolant temperature sender G62

EDC control unit J248

Quantity adjuster N146

Air-mass flow meter G70

Engine speed sender G28

Secondary influencing factors

Modulating piston movement
sender G149

Fuel temperature sender G81

12

Main influencing factors

Pedal position determined by G79

A decisive factor for the injection quantity is the accelera­tor pedal position, i.e. the driver input.
The accelerator position sender is a sliding contact poten­tiometer and includes an idling switch and a kick-down
switch (refer to Function Diagram). From these signals,
the control unit calculates the necessary fuel quantity

SSP 153/13

using additional parameters.

Substitute function

If a fault occurs, the engine runs at a higher idling speed
so that the customer can reach the next workshop.
The accelerator position sender is then deactivated.

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SSP 153/15

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Fuel temperature as determined by G81 and
coolant temperature determined by G62

The control unit calculates the quantity of fuel to be inject­ed. To make a precise calculation, allowance must be
made for the coolant temperature and the density of the
diesel fuel. The temperature of the fuel is therefore deter­mined.
Substitute function for G81 and G62
If one these signals is missing, or both, the coolant and
fuel temperatures are calculated with stored substitute
values.

Engine speed as determined by G28

The engine speed is one of the main factors which the
control unit processes in order to calculate the injection
quantity.

Substitute function

If the engine speed sender is faulty, an emergency run­ning program is activated. The needle lift sender G80
supplies a substitute engine speed signal for this pur­pose.
The injection quantity is reduced, the commencement of
fuel injection is controlled and the charge pressure control
is switched off during emergency operation.
If the substitute engine speed signal of G80 fails as well,
the engine is turned off.

13

Fuel regulation

Main influencing factors

Air mass determined by G70
The air-mass flow meter determines the intake
air mass. A smoke map stored in the control
unit limits the injection quantity if the induced
air mass is too low for smoke-free combustion.

Substitute function

If this signal fails, an emergency program is
activated (refer to page 10).

SSP 153/17

Smoke map

The permissible injection quantity is determined
using the smoke map stored in the control unit.
If the air mass is too low, the injection quantity
is limited to the extent that no black smoke
occurs.

Modulating piston movement determined by G149

To check the quantity adjuster and to calculate the
fuel quantity, the control unit requires feedback on
the actual quantity of fuel injected. Sender G149 is
permanently linked to the eccentric shaft of the
quantity adjuster. It signals the position of the shaft
to the control unit, and thus the exact position of the
modulating piston.

Fuel mass

Air mass

Engine speed

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Substitute function

If the sender fails, the engine is turned off for safety
reasons.

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14

Secondary influencing factors ( as required)

Clutch pedal position determined by F36

Engine shudder suppression is a convenience function of
the quantity control. To suppress engine shudder, the
control unit needs to know whether the clutch is engaged
or disengaged.

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When the clutch is engaged, the injection quantity is
briefly reduced.

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Note: The two switches must be set in such a way that their shift points

Brake pedal position determined by F and F47

The switch supplies the "brake actuated" signal (redun­dant system) for safety reasons.
This is monitored by the control unit. In addition, the two
switches use these signals to check the accelerator posi­tion sender (plausibility).
This prevents the brake being applied at full throttle for
example.

Substitute function

If one of the two switches fails or if the switches are not
set identically, the system activates an emergency run­ning program which intervenes in fuel regulation.

are identical.
A precise adjustment according to the Workshop Manual is
therefore necessary.

15

Fuel quantity control

Function

EDC control unit

The EDC control unit process­es the incoming information.
From this, it calculates the nec­essary injection quantity and
sends control signals to the
quantity adjuster.

Quantity adjuster

Eccentric shaft

Quantity adjuster N146

The quantity adjuster is inte­grated in the distributor injec­tion pump.

The task of the quantity
adjuster is to generate the cor­rect injection quantity from the
control signals.

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Modulating piston

The quantity adjuster is a solenoid, a type of electric motor which adjusts the posi­tion of the modulating piston via an eccentric shaft and thus regulates the fuel quan­tity continuously from zero to max. delivery rate.

16

Injection commencement control

The point of commencement of fuel injection influences various engine characteris­tics, such as starting response, fuel consumption and finally, exhaust emissions.

The task of the injection commencement control is to determine the correct point in
time for fuel delivery.
The EDC control unit calculates the commencement of injection depending on the
influencing factors as detailed below, and issues the corresponding output command
to the commencement of injection valve N108 in the injection pump.

Overview

EDC control unit J248

Engine speed sender G28

Coolant temperature sender G62

Needle lift sender G80

Calculated fuel mass

SSP 153/23

Commencement of injec­tion valve N108

17

Injection commencement control

Influencing factors

Commencement of injection map

A commencement of injection map is stored in the control unit. It essentially makes
allowance for the engine speed and the fuel quantity to be injected. As a correcting
parameter, the coolant temperature also has a bearing on the commencement of
injection.
The map was determined empirically and represents an optimal compromise
between good running characteristics and emission behaviour.

Commencement of injection

Fuel mass

Calculated fuel mass

The point of commencement of injection must be brought forward with increasing
injection quantity and engine speed because the injection cycle takes longer.
The fuel mass to be injected was calculated by the control unit (refer to chapter
"Fuel regulation").
This theoretical value is used in the commencement of injection map.

Engine speed

SSP 153/24

18

TDC signal and engine speed determined by G28

The engine speed sender, in co-operation with the sender
wheel on the crankshaft, supplies a TDC signal to the control
unit for each cylinder.

Substitute function

If engine speed sender G28 is defective, the system activates
an emergency running program for which needle lift sender
G80 supplies a substitute engine speed signal.
In emergency running mode, commencement of fuel injection
is controlled in an open loop only (as opposed to a closed con­trol loop), injection quantity is reduced and the charge pressure control is
switched off.
If the substitute engine speed signal also fails, the engine is turned off.

Coolant temperature as determined by G62

To compensate for the longer firing delay when the engine is
cold, the injection cycle must be advanced.
The temperature signal corrects the map accordingly.

Substitute function

If the temperature sender fails, a fixed coolant temperature is
defaulted.

Point of commencement of injection determined by G80

From the signal supplied by the needle lift sender, the control
unit recognises the actual point of commencement of fuel
injection and compares this with the setpoint as defined in the
commencement of injection map.
If deviations from the setpoint occur, the point of commence­ment of injection is corrected via valve N108.

Substitute function

If the signal is missing, no feedback is provided regarding the commence­ment of injection. The system activates an emergency running program in
which the commencement of injection is only just controlled. The injection
quantity is limited at the same time.

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SSP 153/25

19

Injection commencement control

Injection timing device (schematic diagram)

To provide a better overview, the commencement of injection valve N108 is shown
here rotated through 90°. The diagram shows the point of commencement of fuel
injection adjusted towards "advance".

The mechanical injection timing device in the distributor injection pump operates
using the speed-dependent fuel pressure inside the pump.
The injection timing devices
works by selectively adjusting the
pressure acting on the non­spring-loaded side of
the injection timing
piston.
The pressure is
adjusted by
means of

advance

Fuel pressure
inside the pump

Bolt

Pressure roller

retard

defined pulse

To suction side of
rotary vane pump

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Spring

Injection timing piston

duty factors
which are used to control commencement of injection valve N108, i.e. an exact point
of commencement of fuel injection is assigned to each pulse duty factor.
In this way it is possible to continuously regulate the point of commencement of fuel
injection between max. advance and max. retard.

Commencement
of injection
valve 108

20

Lifting plate

Pressure roller

EDC control unit

From the incoming values, the EDC control
unit calculates the setpoint for injection com­mencement and sends a corresponding pulse
duty factor to commencement of injection valve
N108.

Injection timing piston Commencement of

injection valve N108

Substitute function for N108

If the valve fails, the point of commencement of injection is no longer regulated. Instead it
is permanently defaulted.

Commencement of

injection valve N108

The valve converts the pulse
duty factor into a change in
control pressure which acts on
the non-spring-loaded side of
the injection timing piston.

21

Exhaust gas recirculation

The exhaust gas recirculation (EGR) system is designed to reduce pollutant emis­sions in the exhaust gas.

The direct injection process uses higher combustion temperatures than the chamber
process. The formation of nitrogen oxides (NOx) increases with higher tempera­tures, provided that sufficient excess air is available.

The EGR valve adds a fraction of the exhaust gases to the fresh air supplied to the
engine.
This reduces the oxygen content in the combustion chamber and slows down NOx
formation.

The exhaust gas recirculation rates are, however, limited by a rise in hydrocarbon
(HC), carbon dioxide (CO) and particle emissions.

Regulation of exhaust gas recirculation (schematic diagram)

EDC control unit

Atmospheric
pressure

Vacuum supply

Exhaust gas recircula­tion valve N18

SSP 153/27

Air-mass flow meter G70

Vacuum
Atmospheric pressure
Intake manifold pressure

Charge air cooler

EGR valve

Exhaust gas
Control pressure
Electrical signals

22

Function

Fuel regulation

Air mass

Fuel mass

Engine speed

SSP 153/28

EGR map

An EGR map is stored in the control unit. It
contains the necessary air mass for every
operating point of the engine; this is dependent
on engine speed, injection quantity and engine
temperature.

The control unit recognises from the air-mass
flow meter signal whether the intake air mass
is too high for the vehicle in its momentary
operating state.
To compensate for any deviation, more
exhaust gas is supplied as required.
If the supplied exhaust gas quantity is too high,
the intake air mass decreases. The control unit
then reduces the proportion of the exhaust
gases.

EGR valve

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The EGR valve is mounted in a connecting
duct between the exhaust gas and the intake
pipe.
When the valve is subjected to a vacuum, it
opens and allows exhaust gas to enter the
fresh air flow.

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Exhaust gas recirculation valve N18

Valve N18 converts the signals supplied by the
control units into a control vacuum for the EGR
valve.
It is supplied by the engine's vacuum pump
and is opened by signals from the control unit.
The pulse duty factor of these signals defines
the vacuum which is admitted to the EGR
valve.

23

Charge pressure control

The solenoid valve for charge pressure control N75 applies pressure to the charge
pressure control valve on the exhaust gas turbocharger (waste gate).
Valve N75 receives electrical signals (pulse duty factor) from the EDC control unit.
Charge pressure is thus regulated according to a characteristic map.

Feedback on the actual pressure in the intake pipe is provided along a hose con­nection routed from the intake pipe to a sensor in the control unit.
If a deviation from the setpoint occurs, the pressure is corrected accordingly.
The charge pressure is also corrected in the control unit by the intake pipe tempera­ture to make allowance for the effect of temperature on the density of the charge air.

To ensure that the air mass supplied to the engine stays almost constant, the
charge pressure specified map is corrected in dependence on the air pressure using
the information supplied by the altitude sender F96. The charge pressure is reduced
above an altitude of approx. 1500 m to prevent the turbocharger overspeeding in
excessively thin air.

Charge pressure control (schematic diagram)

EDC control unit

Solenoid valve for charge
pressure control N75

Charge pressure
control valve

Intake manifold pressure sender

Intake manifold
temperature
sensor G72

Charge air cooler

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Atmospheric pressure
Intake manifold pressure

Exhaust gas
Control pressure
Electrical signals

24

Solenoid valve for charge pressure control N75

The EDC control unit sends output signals to the
solenoid valve for charge pressure control N75
according to the charge pressure specified map. By
changing the signal pulse duty factor, more or less
intake manifold pressure is applied to the charge
pressure control valve on the exhaust gas tur­bocharger.
The charge pressure can thus be varied between
the minimum and maximum permissible values.

Direction of continuity:

de-energised:

Atmospheric
pressure

energised:
(max. pulse duty factor)

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Intake mani­fold pressure

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to charge pressure
control valve

Intake manifold temperature sender G72

The charge pressure is also corrected in the control
unit by the intake pipe temperature to make
allowance for the effect of temperature on the densi­ty of the charge air.

25

Glow plug system

A glow plug controller is integrated in the EDC control unit of the 1.9-ltr. TDI engine.
This process is divided into the following phases:

 Glow phase
 Afterglow phase

Glow phase

Thanks to the good starting response of this direct injection diesel engine, a glow
phase is only necessary below + 9°C. The control unit receives the corresponding
temperature signal from coolant temperature sender G62.
The duration of the glow period is dependent on the size of this temperature signal.
The warning lamp for glow period K29 on the instrument panel indicates to the driv­er when the glow phase is in progress.

Please note: The warning lamp for glow period has dual functions. If it comes on

during vehicle operation, it serves as a fault warning lamp and pro­vides the driver with information regarding a fault in the engine man­agement system.

Afterglow phase

The glow phase follows the afterglow phase after starting the engine. This improves

combustion efficiency shortly after the engine is started, and dampens engine noise,
improves idling quality and reduces hydrocarbon emissions.

The afterglow phase always takes place irrespective of glow phase.
The afterglow phase is interrupted at an engine speed of 2,500 rpm.

Engine speed determined by G28

Coolant temperature
determined by G62

EDC control unit

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Glow plugs

Relay for glow
plugs

Fuse

26

Emission characteristics

Minimising environmental pollution demands a great deal of co-ordination
and design work. This frequently involves reconciling conflicting demands
such as low nitrogen oxide emission and high engine performance.
The 1.9-ltr. TDI engine easily achieves the 1998 EU exhaust emission
limits and offers high fuel efficiency at the same time.

Pollutants in the exhaust gas

The pollutants which mainly occur in the exhaust gases of diesel engines
are

 carbon dioxide (CO)
 gaseous hydrocarbons (HC)
 particles
 nitrogen oxides (NOx).

Other noxious components such as sulphur hydrides also occur in small­er quantities.

Carbon dioxide, particles and hydrocarbons in exhaust gas are primarily
due to incomplete combustion of the fuel.
Nitrogen oxides - chemical compounds of oxygen and nitrogen - form at

high combustion chamber temperatures, provided that sufficient excess
air is available.

Pollution control

The proportion of nitrogen oxides (NOx) normally increases due to the
measures to reduce particle and HC formation. Reducing nitrogen oxide
emission means accepting higher emissions of other exhaust gas con­stituents, and possibly even higher fuel consumption. It is also necessary
to find the best possible compromise.

The components involved in the combustion process, e.g. injectors, pis­ton recess, combustion chamber shape, etc, were designed with a view
to minimising exhaust emissions in particular.
The complete engine management system has been adapted in such a
way as to optimise the combustion process.

Above all the point of commencement of injection and the exhaust gas
recirculation affect the composition of the exhaust gas.

27

Effect of the point of commencement of injection

To reduce the proportion of nitrogen oxides in the exhaust gas, the injection cycle
commences slightly later than would otherwise be necessary to develop maximum
power output. This causes an increase in HC and particle formation. Fuel consump­tion increases by approx. 4% because of the delay in commencement of the injec­tion cycle.

Effect of the exhaust gas recirculation

The supply of exhaust gases to the combustion chamber reduces the oxygen com­ponent in the combustion chamber.
This reduces the emission of nitrogen oxides, but it increases particle emission in
certain operating states.
The addition of the recirculated exhaust gas quantity is therefore adapted precisely.

28

Internal functions in the control unit

In the control unit, several auxiliary functions take place continuously dur­ing vehicle operation

Idling speed control

From the engine speed signal, which is supplied 4 times per revolution,
the control unit recognises deviations from the set idling speed at an
early stage. The quantity adjuster in the injection pump then receives a
signal immediately. The idling speed is thus kept constant in every oper­ating state, e.g. when electrical current consumers are switched on.

Even running control

To ensure the engine runs very evenly, the injection quantity of every
cylinder is regulated in such a way that the engine speed signal is uni­form.

Shudder damping

To avoid shudder, which occurs when marked load changes occur, the
information regarding the accelerator pedal position is electronically
"damped" when the pedal is moved too quickly.

Maximum speed cut off

When the maximum engine speed is reached, the control unit reduces
the injection quantity to protect the engine against overspeeding.

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Starting quantity regulation

The injection quantity necessary for starting the engine is dependent on
the coolant temperature. The control unit determines the correct quantity
to keep the exhaust emissions low.

Signal monitoring

The control unit monitors itself and the functions of sensors and actuators
during vehicle operation. The glow plug warning lamp indicates when
major faults occur.

29

Self-diagnosis

The self-diagnosis and safety concept of the EDC (Electronic Diesel

Control)

The control unit assumes the following functions during vehicle operation:

 It continuously cross-checks the measured values supplied by the sen-

sors for plausibility.

 It monitors the electrical and mechanical functional capability of the final

control elements (actuators) by observing system reactions. The self-

diagnosis carries out actual value/setpoint comparisons; the results of

these comparisons must meet the given requirements (maps).

 The self-diagnosis monitors the electrical connectors and cable connec-

tions for cable breakage (open circuit) and short circuit.

D

I
A
G
N
O
S

I
S

If faults occur in the system, the EDC reacts according to
the significance of the fault.

Stage 1: Should any sensors with a correcting function fail, the

EDC uses default substitute values or accepts information

Stage 2: Major faults - i.e. faults leading to the failure of subfunc-

Stage 3: If the drive can no longer control engine power output

from other sensors.
The actions of this correcting function usually stay unno­ticed by the
driver.

tions - result in a reduction in performance, and a warning
is issued to the driver via the fault warning lamp.

with the accelerator pedal, the EDC switches the engine
to high idling speed mode.
In this way, servo functions of the vehicle are preserved
and vehicle operability is retained.

Fault detection

R
E
A
C

T

I
O
N

Stage 4: If reliable engine operation can no longer be ensured, the

quantity adjuster turns the engine off. If this is not possi­ble on account of the fault, the engine is turned off via the
fuel cut off valve (redundant system).

30

Performance diagram

Engine performance and torque

The maximum power output of the new 1.9-ltr. TDI industrial engine is 60
kW (84 bhp) at 3,300 rpm.

The engine is notable for its very good torque curve.
Maximum torque is 205 Nm at only 1800 rpm.

210

200

190

180

170

160

Tq. red.

150

Nm

140

130

120

110

64

60

56

52

48

44

40

36

32

28

24

P red.

kW

100

90

80

70

60

50

1300 1500 1700 1900 2100 2300 2500 2700 2900 3100 3300 3500

Engine speed / rpm

31

20

16

12

8

4

0

Self-diagnosis

Engine data

Type 4-cylinder in-line turbodiesel engine
Displacement 1,896 cm3
Bore 79.5 mm
Stroke 95.5 mm
Compression ratio 19.5:1
Rated output 60 kW (84 bhp) at 3,300 rpm

Max. torque 205 Nm at 1,800 rpm
Mixture preparation Direct injection with electronically regulated

Exhaust gas 96/1/EC (Euro 2)

distributor injection pump

VOLKSWAGEN AG
K-VSI Industrial Engines
Postfach 1961
D-38436 Wolfsburg

Tel. ++49 5361 927164 Fax ++49 5361 9 20650
[e-mail]
http://www.vw-industrial.com

04/99 *** 000.919469.20 *** Printed on non-chlorine bleached paper. *** Technical specifications subject to change without notice.