Draper M111 User Manual
Lotus Service Notes Section EMN
ENGINE MANAGEMENT & FUEL INJECTION
SECTION EMN - M111 ELISE
Section Page
Introduction & Component Location EMN.1 3
'Lotus Check' Scanner Tool EMN.2 4
Throttle Cable Adjustment EMN.3 7
Electronic Control Module (ECM) EMN.4 7
Relay Module EMN.5 8
Manifold Absolute Pressure (MAP) Sensor EMN.6 9
Crankshaft Position Sensor EMN.7 10
Engine Coolant Temperature (ECT) Sensor EMN.8 11
Intake Air Temperature (IAT) Sensor EMN.9 12
Throttle Position (TP) Sensor EMN.10 13
Idle Air Control (IAC) Valve EMN.11 14
Oxygen (O2) Sensor EMN.12 15
Camshaft Position Sensor (VVC only) EMN.13 16
VVC Mechanism Control Solenoids (VVC only) EMN.14 17
Oil Temperature Sensor (VVC only) EMN.15 18
Fuel System EMN.16 19
Ignition System EMN.17 24
Page 1
Lotus Service Notes Section EMN
COMPONENT LOCATION DIAGRAM em196
Page 2
Lotus Service Notes Section EMN
EMN.1 - INTRODUCTION
Key to Component Location Diagram
1. Fuel pump 14. Cam angle sensor (VVC only)
2. Engine coolant temperature (ECT) sensor 15. Idle air control (IAC) valve
3. Water temperature gauge sender (vertical) 16. Throttle postion (TP) sensor
4. Crankshaft position sensor 17. Throttle body
5. Oxygen sensor 18. Relay module
6. Intake air temperature (IAT) sensor 19. Data link connector (DLC)
7. Oil temperature sensor (VVC only) 20. Electronic control module (ECM)
8. VVC control solenoids 21. Inertia switch
9. Fuel injector 22. Vehicle speed sensor
10. Fuel pressure regulator valve 23. Fuel filter
11. Fuel rail 24. Distributor (std. only)
12. Manifold air pressure (MAP) sensor (VVC only) 25. Evaporative emissions canister
13. Ignition coil (std. and VVC shown)
The 1.8 K Series engine fitted to the Elise is equipped with a Modular Engine Management System
(MEMS), version '1.9' for the standard engine, and version '2J' for the VVC engine, abbreviated to 'MEMS 1.9'
or 'MEMS 2J'. Both versions use a single electronic control module (ECM) to control both the fuel injection and
ignition systems, and base the control strategy on engine speed/air density measurement. Engine speed data
is derived from a flywheel sensor, with air density calculated from manifold air pressure and manifold air
temperature signals.
The engine features a throttle body housing a single throttle butterfly valve, with position sensor, feeding
into an intake plenum chamber with four individual intake tracts, each of which is fitted with a fuel injector
positioned to spray fuel onto the back of the intake valves. Standard engines use a lightweight moulded plastic
plenum/manifold, whereas on VVC engines, the manifold is alloy. Fuel delivery quantity is controlled by the
length of time (pulse width) for which the solenoid operated injectors are energised, with the injectors of
standard engines grouped in pairs, 1 with 4, and 2 with 3, whereas the VVC engine uses a fully sequential
strategy with individual control of each injector.
The air/fuel ratio is calculated by the ECM using a three dimensional map to provide a basic fuelling
specification under various operating conditions. In order to refine the fuel delivery and cater for special
conditions, various types of compensation are provided:
- Cranking enrichment; During cranking, when engine speed is below about 400 rpm, the injection pulse
width is increased, dependent on coolant temperature, to aid starting.
- After start enrichment; Immediately after starting, the pulse width is increased, but decays at a rate
dependent on coolant temperature.
- Acceleration enrichment; Signals received from the throttle position and MAP sensors which indicate
acceleration is demanded, will prompt additional fuel for smooth and ready response.
- Overrun fuel cut-off; At normal running temperature, when the throttle is closed and engine speed is
above about 2,000 rpm, indicating engine overrun, the fuel supply is shut off to enhance economy and
reduce emissions.
- Overspeed fuel cut-off; At a specified engine speed, the injectors are cut off in order to protect the engine
from overspeeding.
- Oxygen sensor feedback; By measuring the oxygen content of the exhaust gas, any adjustment neces-
sary to maintain the air/fuel ratio to that required by the catalytic converter for optimum conversion
efficiency may be computed by the ECM. An electrically heated oxygen sensor is used to ensure its
speedy attainment of working temperature after a cold start.
- Battery voltage correction; The ECM senses battery voltage, and applies a correction factor to take
account of any variation in fuel delivery due to battery voltage fluctuation.
An idle air control valve mounted on the throttle body, is used to regulate the amount of air by-passing the
throttle plate, and hence control engine idle speed.
Two types of ignition system are used, both controlled by the ECM. Standard engines use a single
ignition coil mounted on the right hand side of the cylinder block, and a distributor driven from the rear end of
the inlet camshaft. VVC engines use a distributorless ignition system (DIS) which employs a pair of double
ended ignition coils and a 'waste spark' system whereby each coil fires two spark plugs simultaneously (1
Page 3
Lotus Service Notes Section EMN
paired with 4, and 2 with 3), the spark in the cylinder on the exhaust stroke being 'wasted'. The twin coil pack
is mounted on the cylinder block as for standard engines.
On VVC engines, the variable valve control mechanism is also controlled by the ECM. Two solenoid
valves attached to the hydraulic control unit on the inlet camshaft mechanism are used to distribute oil pressure either side of a piston in order to alter the amount of inlet cam cyclical speed variation, and corresponding
valve timing.
The ECM is calibrated to recognise sensor readings which are outside of the acceptable range, and if
such a signal is received from the coolant sensor, inlet air temperature sensor, or MAP sensor, it will substitute
a default value to enable the engine to continue to run, in a 'back up', or 'get you home' mode. As a vehicle
security measure, the engine management ECM incorporates an immobilisation feature, whereby a coded
signal must be received from the security '5AS' module before the starter and ignition circuits become active.
For security details, see electical section MN, or the 'Lotus Check' instruction booklet.
EMN.2 - 'LOTUS CHECK' SCANNER TOOL
In order to provide for communication with the engine management system electronic control module, a
hand held electronic scanner tool, 'Lotus Check' (part number T000T1346), may be plugged into a special 16
terminal harness connector socket, known as a Data Link Connector (DLC), located in the rear luggage compartment.
Cars without 'bootbox' (pre Sept. '98) 'Bootbox' cars (post Sept. '98)
Data
Link
Connector
em194 ohs82
The 'Lotus Check' tool allows the following operations to be performed:
- PRE-TEST; This is used to check whether any faults have been detected since the last pre-test.
- TEST; This runs a test sequence for various engine management components.
- LIVE DATA; This programme enables current readings from various sensors to be displayed or printed.
- PROG; Applicable only to VVC models - allows matching of engine and security modules after unit
replacement.
- TUNE; Applicable only to VVC models - checks and calibrates certain components.
Contents of the Lotus Check Tool T000T1346
The Lotus Check Tool T000T1346 is supplied in a plastic case, and contains the following items:
- Scanner Tool with LCD display panel;
- Printer;
- Power Harness;
- Adaptor Harness;
- MEMS 1.9 Programme Card;
- MEMS 2J Programme Card;
- 5AS Security Programme Card;
- Security Module ('Dongle');
- Instruction Booklet.
Page 4
Lotus Service Notes Section EMN
Adaptor harness
plugged into DLC MEMS 1.9
& switched to Power or MEMS 2J
'MEMS' harness programme
card
Printer
Connect to battery Scanner tool em192
To Connect 'Lotus Check'
To connect the equipment, proceed as follows:
i). Plug the power harness into the scanner tool and the printer;
ii). Insert the MEMS 1.9 (standard engine) or MEMS 2J (VVC engine) programme card into the scanner tool
slot, label uppermost.
iii). Open the front and rear compartment lids;
iv). Connect the power harness crockodile clips to the battery in the front compartment;
v). Plug the adaptor harness into the 16 terminal diagnostic link connector (DLC);
vi). Select 'MEMS' on the adaptor harness switch;
vii). Press F2.
Pre-Test
Whenever the ignition is switched on, or the engine is running, the ECM monitors the readings of all the
sensor inputs, and compares them with pre-programmed tolerance bands. If any readings should fall outside
of these tolerances, the fault will be recorded in memory, and a substitute 'default' value used to enable the
engine to continue to run at a reduced performance level. If the fault is intermittent, and is no longer present
when the ignition is next turned on, the ECM will reinstate the sensor input, but will record the fault in memory.
Dependent on the nature of the fault, this may or may not have been noticed by the driver.
At each maintenance service, the 'Lotus Check' tool should be connected, and the Pre-Test selected from
the main menu to check whether any faults have been detected since the last Pre-Test. This test takes only a
few minutes, during which the scanner display will ask a series of questions and issue instructions to guide the
operator through the test, which is self explanatory, with the following special notes;
'Is fuel rail temperature sensor fitted?' - answer 'NO'.
'How many cooling fans are fitted?' - answer '1'.
References to a 'current clamp' are not applicable in this application - answer 'Proceed'.
After the test has been run, a print out should be obtained as the results are not displayed in any other
manner. If any 'default flags' are shown, the Pre-Test should be run again to establish whether the fault is still
current. If not current (i.e. the fault is intermittent, and is no longer detected), the memory will be cleared of the
default flag, and the next time the test is run, no flag will be shown. Be aware that if a successful repair is
made, the next time a Pre-Test is run, the fault will still be flagged, as having been detected since the previous
Page 5
Lotus Service Notes Section EMN
test. Run a further test to verify the repair.
Prog
The 'programme' menu is available only on the MEMS 2J card, and allows matching of the engine
management and security 5AS modules if one or the other is replaced. At the instant of ignition is switch on,
the security 5AS module sends a unique coded signal to the engine management ECM, which must be recognised by the ECM before it will allow the engine to run. If no code, or an incorrect code is received, the ECM
will prevent fuelling of the engine, although the engine may crank - typically resulting in engine start followed
immediately by a stall. If either the engine ECM or security 5AS module is replaced, or swopped from another
vehicle, the ECM must be taught to recognise the coded 5AS signal by selecting 'MEMS MATCHING' from the
'PROG' menu and following the instructions.
When mems matching is complete, it is then necessary to select 'CALIBRATION ID' from the 'PROG'
menu to complete the operation - Unless this is performed, the engine will not run.
Note that for standard cars, ECM matching can only be carried out using the '5AS' card and security
password system - refer to service notes sub-section MN.2.
Test
This programme is more comprehensive than the Pre-Test, and takes about 10 minutes to complete tests
on many of the engine management components. During this routine, the scanner display will ask a series of
questions and issue instructions to guide the operator through the test, some parts of which require that the
engine be run up to normal operating temperature. The test should be used any time that a driveability concern
is reported, or if the Pre-Test does not identify the problem.
Components tested in this routine include:
- Coolant temperature sensor;
- Fuel injectors;
- Fuel pump;
- Oxygen sensor heater relay;
- Purge valve solenoid;
- VCC control solenoids (note that it is not normally possible to hear these solenoids operate);
- Throttle position sensor;
- Cooling fan;
- Tachometer;
- Idle air control motor;
- Oxygen sensor;
The test results should be printed out to identify any detected faults. If a fault is recorded, note that
problem may be in the component or the associated circuitry. Refer to the appropriate EMN sub-section or
circuit diagram to diagnose the fault. Displaying 'Live Data' (see below) may also help diagnosis.
Live Data
This programme, which requires the ignition to be switched on, allows readings from various sensors to
be displayed with or without the engine running. This facility may also be used to observe the sensor readings
whilst the car is being driven, which may help to identify an intermittent problem. Requesting a print, will freeze
the data at that instant and print out a complete list. Comparison of data with a known good car may help to
identify a problem. Erroneous readings may be due to a faulty sensor, or its associated circuitry; refer to the
appropriate EMN sub-section or circuit diagram.
Engine parameters monitored include:
- Engine rpm;
- Manifold vacuum;
- IAC valve position;
- Throttle position sensor reading;
- Coolant temperature;
- Inlet air temperature;
- Oxygen sensor voltage.
Tune
The 'test' programme is available only on the MEMS 2J card, and allows the oxygen sensor circuit to be
tested and the IAC valve to be tested and reset without performing a full 'test' programme.
Page 6
Lotus Service Notes Section EMN
EMN.3 - THROTTLE CABLE ADJUSTMENT
Before adjusting the cable, first check that the pedal end of the cable is correctly located, and that the
cable is correctly routed with no sharp bends or entrapment. Do not attempt to adjust the throttle cable or idle
speed by means of the stop screw on the throttle body, which should not be disturbed.
The throttle cable and associated components must be adjusted in a specific sequence to ensure full and
correct throttle operation without cable strain. The procedure is detailed in sub-section JH.8 but may be
summarised as follows:
- Adjust the pedal upstop for a pedal height 30mm below brake and clutch pedals.
- Adjust the ball jointed pull rod connecting to the pedal to achieve a gap of 20mm between outer cable
abutment and multiplier lever pivotting link.
- Adjust the locknuts at the engine end of the outer cable to allow a small amount of free play to accommodate temperature change effects.
- Adjust the pedal downstop so that full travel of the throttle butterfly can just be achieved without allowing
the cable to be strained.
EMN.4 - ELECTRONIC CONTROL MODULE (ECM)
The ECM is an electronic processor mounted on a panel either at the left hand side of the rear luggage
compartment (pre 'bootbox') or at the rear of the engine compartment (with 'bootbox'). The immobilisation
feature of the vehicle security system results in the ECMs for engine management and security being match
coded, such that the engine module must recognise a coded signal from the security module before the unit
becomes operative.
The engine ECM is an adaptive unit which 'learns' the optimum setting of the idle air control valve, and
the fuelling offset required to achieve the correct exhaust oxygen content for a particular engine relative to its
wear and performance characteristics. This feature speeds the response of the system, and minimises the
time spent adjusting to changed operating conditions.
A summary of the sensors supplying inputs to the ECM, and the components to which the ECM supplies
output control, follows:
Inputs Outputs
Crankshaft position Ignition coil
Manifold absolute pressure Fuel injectors
Engine coolant temperature Idle air control valve
Intake air temperature Fuel pump relay
Exhaust oxygen content ECM Diagnostic connector
Throttle position Oxygen sensor heater relay
Camshaft position (VVC) VVC control solenoids
Oil temperature (VVC) Main relay
Diagnostic input Radiator cooling fans
Battery supply
Starter signal
Earth supply
Vehicle security signal
Note that the ECM on 'bootbox' cars built between September '98 and February '00 was originally mounted
on the front side of the composite bootbox. In order to improve electromagnetic shielding, a steel mounting
plate was introduced to secure and earth the ECM directly to the rear subframe. All such cars should be retrofitted with this steel mounting bracket.
If a replacement engine ECM is fitted (or security 5AS module), the Lotus Check tool must be used to
match the engine management and security modules. VVC models may use the MEMS 2J card for this
operation (see EMN.2), whereas standard cars must use the security 5AS card and the password system (see
section MN.2.
Page 7
Lotus Service Notes Section EMN
Before removing an ECM, first disconnect the battery earth lead before pressing the retaining barb and
unplugging the harness connector(s). On standard cars, the MAP sensor is contained within the ECM body,
with the sensor hose connecting to a spigot on the underside of the unit. On pre 'boot box' cars, release the
three screws securing the ECM to the side panel, and withdraw the unit. On post Sept. '98 'bootbox' cars, the
ECM is mounted at the rear of the engine bay, standard modules fixed to the bootbox front wall, and VVC
module using a steel mounting bracket. To release the VVC module, undo the clamp top bolt, the second ECM
top fixing, and lift out the ECM.
Early type mounting
in luggage bay
ECM
em197
MAP sensor hose
VVC type
ECM top fixing Clamp top fixing
EMN.5 - RELAY MODULE
em222a
The MEMS relay module is single unit serviced only as one component. The unit incorportates the
following relays:
- Main Relay; Supplies current to the ECM when the ignition is switched on. When the ignition is switched
off, the ECM will keep the main relay energised for a short period whilst the IAC valve is driven to its
power down position, ready for the next engine start.
- Fuel Pump Relay; Energised by the ECM for a 3 second period each time the ignition is switched on.
Continuously fed during engine cranking and while the engine is running.
- Starter Relay; Energised by the cranking output from the ignition switch. Supplies current to the starter
motor solenoid.
- Oxygen Sensor Heater Relay; Energised by the ECM to supply current to the oxygen sensor heating
element.
The unit is mounted adjacent to the engine management ECM, either at the left hand side of the rear
luggage compartment on pre 'bootbox' cars, or, on later cars, at the rear of the engine bay on a tongue fixed to
the rear subframe.
If any of the above functions are faulty, the relay module should be replaced: Pull the module off its
mounting tongue, and release the two harness connector blocks (press the retaining clips). On re-assembly,
ensure the connector blocks are fully engaged by the retaining clips.
Page 8
Loading...