Lotus Elise / Lotus Exige. Instruction - part 40

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Lotus Service Notes   

 

 

  Section EMP

Vehicle Speed Sensor            P0500

P0500  Vehicle Speed Sensor “A”

Description

The ECU uses the left rear wheel speed sensor to determine vehicle speed.  This output to the ECU is via the 

ABS module.

Sensor connections

ABS Control Unit    Description                ECU Pin    ECU Connector

3              Wheel Speed 3 from ABS (LR)    77 (B4)    28 Way (Left) 

'06 M.Y. in brackets

Sensor characteristics

Hall Effect sensor

Malfunction Criteria

•  TPS < 0.8

•  Engine speed > 1800rpm and < 5010rpm

•  Baro > 756 mbar

Monitor: Continuous

Potential failure modes:

•  Open or short in vehicle speed sensor circuit

•  Build up of debris in the sensing plate on the wheel hub

Notes:

The MIL will be illuminated if the fault is present for 2 consecutive trips.

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  Section EMP

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Idle Speed Control              P0506

                          P0507

                          P0508

                          P0509

P0506  Idle Air Control System RPM Lower Than Expected

P0507  Idle Air Control System RPM Higher Than Expected

P0508  Idle Air Control System Circuit Low (prior '06 M.Y.)

P0509  Idle Air Control System Circuit High (prior '06 M.Y.)

Description

Prior to '06 M.Y. the ECU controls the air entering the engine with an idle air control (IAC) valve. To increase the 

idle the ECU commands the IAC to open up. This allows more air to bypass the throttle blades. To decrease 

the idle speed the ECU commands the IAC to close up. This will reduce the amount of air bypassing the throttle 

body. The ECU performs low and high circuit checks when it is activating the component.

For '06 M.Y. onwards, the electronically controlled throttle needs no IAC, as the ECU commands the throttle 

valve itself to control idle speed.

Component connections (prior to '06 M.Y.)

Connector    Description          ECU Pin    ECU Connector

1          Idle air control value    35       52 Way

2          Battery Voltage       -        -

3          Ground            -        -

Malfunction Criteria

P0506 – This code is set if the engine fails to achieve the desired idle speed by more than 100 rpm.

P0507 – This code is set if the engine fails to achieve the desired idle speed by more than 200 rpm.

P0508 – This is set when the ECU does not get the expected feedback (prior to '06 M.Y.).

P0509 – This is set when the ECU does not get the expected feedback (prior to '06 M.Y.).

Enable Criteria:

•  Engine at idle speed

•  Battery Voltage between 10 – 16 V

•  Idle speed learn limit ± 15%

•  Timer expired 5 seconds

Monitor: Continuous

Potential failure modes:

•  Throttle body sticking (not fully closing) (prior to '06 M.Y.)

•  Connector / wiring corroded or loose connections (prior to '06 M.Y.)

•  Throttle linkage / cable binding (prior to '06 M.Y.)

•  Induction system air leak

•  Excessive engine load from front end accessory drive system, e.g. water pump seizing

Notes:

The MIL will be illuminated if the fault is present for 2 consecutive trips.

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  Section EMP

Battery Voltage                P0562

                          P0563

P0562  System Voltage Low

P0563  System Voltage High

Monitor: Continuous

Enable Criteria:

•  Engine running

•  P0562 – Voltage Too Low < 10V

•  P0563 – Voltage Too High > 16V

Disable Criteria: None

Potential failure modes:

•  Alternator fault

•  Battery fault

Notes:

The MIL will be illuminated if the fault is present for 2 consecutive trips.

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  Section EMP

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ECU Integrity                  P0601

                          P0606

P0601  Checksum

P0606  Watchdog

Description

These codes are used by the ECU to check the integrity of the software and calibration data. P0601 checks 

that on power up the checksum for calibration data is the same as checksum saved on power down. P0606 

checks the watchdog timer after a defined period to see if it has reset. If the watchdog timer has not reset then 

the code has entered an unplanned loop or condition stopping it resetting the timer.

Monitor

•  P0601 at ECU power up

•  P0606 continuously while the engine running

Notes:

The MIL will be illuminated if the fault is present for 2 consecutive trips.

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