Lotus Evora. Manual - part 31

 

 

Lotus Service Notes   

 

 

  Section EMR

Idle Speed Control

                         

P0506  Idle Air Control System RPM Lower Than Expected

P0507  Idle Air Control System RPM Higher Than Expected

Description

The ECM controls the engine idle speed using a combination of spark advance and throttle blade adjustment. 

If this control cannot attain the desired idle speed a fault is diagnosed. 

Monitor: 

•  Continuous

Enable Criteria:

•  Engine at idle speed

•  Battery voltage between 10 V and 16 V

Malfunction Criteria 1: 

•  Idle air learn value on upper limit of +1.8g/s

•  Idle speed more than 200 rpm above desired idle speed for more than 5 seconds.

Malfunction Criteria 2: 

•  Idle air learn value on lower limit of -1.8g/s

•  Idle speed more than 100 rpm below desired idle speed for more than 5 seconds.

Potential failure modes:

•  Induction system air leak

•  Excessive engine load from front end accessory drive system, water pump, power steering, alternator

•  Electronic Throttle Control

Diagnostic Mask:

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

Notes:

There will be a different learn value for AC on and AC off.  Either could trigger fault

2009/02

 

 

Lotus Service Notes   

 

 

  Section EMR

A/C Evaporator temperature sensor

P0537  A/C Evaporator temperature sensor circuit low

P0538  A/C Evaporator temperature sensor circuit high

Description

The A/C system incorporates an evaporator temperature sensor for system control. This is a thermistor device 

that changes resistance with temperature. As the evaporator temperature decreases the thermistor resistance 

value increases, and conversely as the evaporator temperature increases so the thermistor resistance value 

decreases.

Sensor connections                           

Sensor Connector    Description                  ECU Pin    ECU Connector

1              Sensor signal                A3       48 Way (Right)

1              Sensor ground                K3       48 Way (Right)

Monitor: 

•  Continuous

Enable Criteria: 

•  Vehicle Running

Disable Criteria: 

•  None

Malfunction Criteria: 

•  P0537 – Signal voltage < 0.049V for 1.5 seconds

•  P0538 – Signal voltage > 4.399V for 1.5 seconds

Potential failure modes:

•  Thermistor wiring open circuit or shorted

•  Thermistor fault

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

Battery Voltage

P0562  System Voltage Low

P0563  System Voltage High

Description

With a battery and alternator functioning as normal the system voltage for a running engine should be around 

14V. The ECM monitors this and will diagnose if the voltage is too high or too low.

Monitor: 

•  Continuous

Enable Criteria: 

•  Engine running

Disable Criteria: 

•  None

Malfunction Criteria: 

•  P0562 – Voltage Too Low < 10V for 10 seconds

•  P0563 – Voltage Too High > 16V for 25.5 seconds

Potential failure modes:

•  Alternator fault

•  Battery fault

Diagnostic Mask:

•  The MIL will be illuminated if a fault is present for two consecutive trips.

 

2009/02

 

 

Lotus Service Notes   

 

 

  Section EMR

Cruise Control

P0564  Cruise control multi-function input signal

P0578  Cruise control multi-function input “A” circuit stuck

P0571  Brake switch “A” circuit

Description

Cruise control requests are made using a multi-function switch input. Each cruise control function switch selects 

a different resistive network to a single ECM input. From this input the ECM determines the driver request.

In addition cruise control is cancelled by the application of either the brake pedal or the clutch pedal (see also 

P0806, P0807 and P0808).

Sensor connections                           

Sensor Connector    Description                    ECU Pin    ECU Connector

1              Cruise control switch input          E3       48 Way (Right)

2              Cruise control ground             K3       48 Way (Right) 

1              Brake Switch Ground              -        -

2              Brake Switch Input               C4          48 Way (Right)

P0564, P0578

Monitor: 

•  Continuous

Enable Criteria: 

•  None

Disable Criteria: 

•  None

Malfunction Criteria: 

•  P0564 – Cruise control multifunction switch open circuit or short circuit

•  P0578 – Input other than OFF received for more than 100 seconds

Potential failure modes:

•  Cruise switch wiring open circuit or shorted

•  Cruise switch fault

•  ECU input circuit fault

Notes:

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

previous two trips.

P0571

Monitor: 

•  Continuous

Enable Criteria 1: 

•  KMH > 10 kmh

•  PPS > 0.488%

Enable Criteria 2: 

•  ABS communications working

Disable Criteria: 

•  None

2009/02