Lotus Elise / Lotus Exige. Instruction - part 39

Page 30

 

 

Lotus Service Notes   

 

 

  Section EMP

Purge valve stuck open

A purge valve that is unable to seal correctly will result in a tank evacuation during the sealing phase of the 

leak check sequence. In this phase, a pressure rise would normally be expected but when the purge valve 

is not sealing this causes depression in the tank. When the pressure is below -1.7mbar a purge valve fault is 

detected. 

Purge valve stuck closed

A purge valve that is unable to open will not be able to achieve the required depression during the evacuation 

phase. A positive pressure rise during the leak check evacuation phase will be detected. Additional purge checks 

will set a purge valve fault code.

Monitor: Until leak check is completed

P0442 

This code is set during the evaporative leak check process if the system calculates the measure of leak is above 

a specified value (determined by a table related to fuel level) after the 6.3 second timer has expired.

Monitor: Until leak check is completed

Potential failure modes:

•  Leak from pipes or connections

•  Leaking or damaged seal on filler cap / not fitted correctly

•  Canister Closure valve not fully closing

P0455

This code is set if during the evaporative leak check the system fails to reach the evacuation target pressure. 

The system will perform additional purge checks to determine the nature of the problem. The additional purge 

checks will also run if the leak check fails to complete because the calculated vapour concentration is above 

the limit.

Additional Purge Check Enable Criteria:

•  Vehicle not stationary

•  Load between 30 – 35%

•  Purge value >= 75%

Monitor: Until leak check is completed

Potential failure modes

•  Fuel filler cap not fitted

•  Leak from pipes or connections

•  Canister Closure valve stuck open

P0456

This code is set during the evaporative leak check process if the system calculates the measure of leak is above 

a specified value (determined by a table related to fuel level) after the 19.7 second timer has expired.

Monitor: Until leak check is completed

Potential failure modes:

•  Leak from pipes or connections

•  Leaking or damaged seal on filler cap / not fitted correctly

•  Canister Closure valve not fully closing

Notes:

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

•  Further information on the sensor may be found in Toyota 1ZZ-FE, 2ZZ-GE instruction RM733E (B120T0327J) 

page FI-53

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Lotus Service Notes   

 

 

  Section EMP

Page 31

Evaporative Emission Control – Purge, Open / Closed Circuit        P0444

                                                P0445

                                                P0446

                                                P0447

                                                P0448

                                                P0451

                                                P0452

                                                P0453 

P0444  Evaporative Emission System Purge Control Valve Circuit Open

P0445  Evaporative Emission System Purge Control Valve Circuit Closed

P0446  Evaporative Emission System Vent Control Circuit

P0447  Evaporative Emission System Vent Control Circuit Open

P0448  Evaporative Emission System Vent Control Circuit Closed

P0451  Evaporative Emission System Pressure Sensor/Switch Range/Performance

P0452  Evaporative Emission System Pressure Sensor/Switch Low

P0453  Evaporative Emission System Pressure Sensor/Switch High

Description

When the engine is running the ECU continuously monitors the feedback signals from the evaporative emission 

components. The feedback signal should be low when the turned ON and high when turned Off. The following 

codes will be set if the above conditions are not met.

P0444, P0445, P0447, P0448, P0452, P0453

P0446

This code can be caused by the canister closure valve (CCV) being either stuck closed or open.

CCV stuck open:

A CCV is stuck open then there will be minimal tank depression when the leak test is performed. Addition check 

will be performed when the vehicle is being driven before the code is set. 

CCV stuck closed:

Detection of a stuck closed CCV is implemented by detecting an excessively low tank pressure during normal 

purge. Detection of this fault will disable further purging 

Additional checks for stuck CCV closed:

•  Vehicle not stationary

•  Load between 30 – 35%

•  Purge Value >= 75%

Monitor: Until leak check is completed.

P0451

This code is set when the ECU detects abnormalities in the fuel tank vapour pressure sensor signal. The ECU 

analyses the filtered and unfiltered pressure signal at idle after a de-slosh period to determine if there is any 

difference, a big difference indicates as fault. The ECU also monitors the signal on gear changes to see if there 

is any pressure rise as a result of the fuel sloshing around.

Disable Criteria:

P0500 – Wheel speed sensor fault

Monitor: Until leak check is completed

Notes:

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

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Lotus Service Notes   

 

 

  Section EMP

Fuel Level Sensor              P0461

                          P0462

                          P0463

P0461  Fuel Level Sensor “A” Circuit Range/Performance

P0462  Fuel Level Sensor “A” Circuit Low

P0463  Fuel Level Sensor “A” Circuit High

Description

When the engine is running the ECU continuously monitors the fuel level sensor feedback signals. The feedback 

signal should be low when turned ON and high when turned OFF. The following codes will be set if the above 

conditions are not meet.

Sensor connections                           '06 M.Y. in brackets

Sensor Connector    Description                    ECU Pin    ECU Connector

1              Vapour pressure and fuel level ground   78 (L4)    28 Way (Left)

2              Fuel level sensor                76 (E3)    28 Way (Left) 

3              Vapour pressure & fuel level V ref.      55 (M4)    28 Way (Left)

Enable Criteria:

•  P0462 & P0463 – Condition not met as above

•  P0461 – Checks for three conditions, stuck when full, stuck when empty or stuck midway. The ECU determines 

if the sensor is stuck by calculating the amount of fuel used during the test period with the engine conditions 

as listed below. 

•  RPM > 2800rpm

•  Load > 40%

•  Minimum Fuel level > 2 litres (0.5 US gallons)

•  If the ECU calculates that no fuel has been used during these tests it indicates that the sensor is not work-

ing correctly. The ECU also monitors the filtered and unfiltered signal at idle after a 10 second de-slosh period 

and compares the differences. Gear changes cause the fuel to slosh around so the ECU monitors the signal 

to see if there is any pressure rise. 

Disable Criteria:

P0500 – Wheel speed sensor fault

Notes:

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

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Lotus Service Notes   

 

 

  Section EMP

Page 33

Engine Cooling Fan Control        P0480

                          P0481

P0480  Fan 1 Control Circuit

P0481  Fan 2 Control Circuit

Component connections

Sensor Connector    Description    ECU Pin    ECU Connector

2 (ACCM 2*)      Relay #1     67 (J2)    28 Way (Left)     

'06 M.Y. in brackets

3 (ACCM 2*)      Relay #2     60 (J3)    28 Way (Left)

*ACCM – A/C Control Module

Monitor: Continuous

Enable Criteria: Engine running

Disable Criteria: None

Potential failure modes:

•  A/C Control Module failure

•  ECU output circuit failure

Notes:

No MIL will be illuminated for this failure.

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