Lotus Evora. Manual - part 37

 

 

Lotus Service Notes   

 

 

  Section EMR

Pedal Position Sensor/Switch 'D'/'E' Voltage Correlation

P2138  Pedal position sensor/switch ‘D/E’ voltage correlation

Description

Two potentiometers are built into the throttle pedal unit in order to provide a throttle demand signal to the ECU.  

Two processors within the ECU compare the two output signals, which should match within a defined tolerance. 

Note that the potentiometers operate on 5 volts.

Enable Criteria: 

•  None

Disable Criteria: 

•  None

Potential failure modes:

•  PPS1 reading incorrectly

•  PPS2 reading incorrectly

Notes: A maximum throttle opening of 15% may be imposed.

Throttle Actuator Control System – High Airflow Detected

P2173  Throttle actuator control system – high airflow detected

Description

The mass air flow is compared with the throttle position to determine whether an incorrect correlation exists.

Enable Criteria: 

•  None

Disable Criteria: 

•  MAF fault(s) present

Potential failure modes:

•  Throttle plate damage

•  Air leak in intake system

Notes: A mechanically sprung 7% throttle opening may be imposed, or the injectors may be shut off to stop 

the engine.

2009/02

 

 

Lotus Service Notes   

 

 

  Section EMR

A/C Refrigerant Distribution Valve

P2612  A/C Refrigerant Distribution Valve Control Circuit Low

P2613  A/C Refrigerant Distribution Valve Control Circuit High

Description:

The A/C refrigerant flow is regulated by the ECM using the distribution valve to control the evaporator to the 

required temperature and prevent freezing.

Component connections:

Connector  Description            ECM Pin   ECM Connector

1          Control valve driver       K3          48 Way (Centre)   

2          Ignition via rear ign relay    -        -

Monitor: 

•  Continuous

Enable Criteria: 

•  Engine running

Disable Criteria: 

•  None

Potential failure modes:

•  P2612 – valve wiring open circuit or shorted to ground

•  P2612 – loss of power from rear ignition relay

•  P2613 – valve circuit, ECM side, shorted to battery voltage

•  Valve failure

•  ECM output circuit failure

Diagnostic Mask:

•  The service light will be illuminated for 30 seconds after engine start if the fault has been present for the

previous two trips.

2009/02

 

 

Lotus Service Notes   

 

 

  Section EMR

A/C Compressor Lock Sensor Circuit

B1422  A/C Compressor Lock Sensor Circuit

Description:

The ECM monitors the A/C compressor speed. If this speed is lower than the engine speed the ECM will turn 

off the A/C compressor clutch. This is to prevent belt damage due to slippage.

Component connections:

Connector  Description      ECM Pin   ECM Connector

1        Lock sensor +ve  C1          32 Way (Left)   

2        Lock sensor -ve    B1          32 Way (Left)

Monitor: 

•  Continuous

Enable Criteria: 

•  Engine running

Disable Criteria: 

•  P0646, P0647 A/C compressor clutch fault

Malfunction Criteria: 

•  A/C compressor speed error greater than 20%

Potential failure modes:

•  A/C compressor clutch mechanism slipping or seized

•  A/C compressor drive belt slipping

•  Lock sensor wiring

•  Lock sensor failure

•  ECM input circuit failure

Diagnostic Mask:

•  The service light will be illuminated for 30 seconds after engine start if the fault has been present for the

previous two trips.

2009/02

 

 

Lotus Service Notes   

 

 

  Section EMR

Lost Communications with TCM

U0101  Lost Communications with TCM

Description:

The ECM communicates with the Transmission Control Module (TCM) via the CAN bus.

If these CAN bus communications have been interrupted the ECM will register a diagnostic code.

Potential failure modes:

•  CAN wiring

•  TCM control module failure

•  CAN bus corruption by another module on bus

Diagnostic Mask:

•  The service light will be illuminated for 30 seconds after engine start if the fault was present on the previous

trip.

Lost Communications with VDCM

U0122  Lost Communications with VDCM

Description:

The ECM communicates with the Vehicle Dynamic Control Module (VDCM) via the CAN bus.

If these CAN bus communications have been interrupted the ECM will register a diagnostic code.

Potential failure modes:

•  CAN wiring

•  VDCM control module failure

•  CAN bus corruption by another module on bus

Diagnostic Mask:

•  The service light will be illuminated for 30 seconds after engine start if the fault was present on the previous

trip.

Lost Communications with TPMS

U0127  Lost Communications with TPMS

Description:

The ECM communicates with the Tyre Pressure Monitor System (TPMS) via the CAN bus.

If these CAN bus communications have been interrupted the ECM will register a diagnostic code.

Potential failure modes:

•  CAN wiring

•  TPMS control module failure

•  CAN bus corruption by another module on bus

Diagnostic Mask:

•  The service light will be illuminated for 30 seconds after engine start if the fault was present on the previous

trip.

2009/02