Fault Conditions

EVAP Purge Valve. Performance Problem.







Fault symptoms
- Market US/CA: CHECK ENGINE.

On-Board Diagnostics
Type of diagnosis:
- Once per driving cycle. Interrupted when fault criteria fulfilled or OK reported. Restarts next driving cycle.
Test 1
Enable criteria:
- Coolant temperature when starting between 5-40 °C. Purging is not active. Idling speed. Max. one change of status of the brake light switch. Volume of fuel in tank between 9-54 liters. The vehicle at a stand still for 5 sec.
When the above conditions are fulfilled for more than 5 sec. the diagnosis will start. Should the diagnosis be interrupted the speed must exceed 0 on one occasion before the diagnosis is allowed to be restarted. The diagnosis continues then as follows:
The shut-off valve is activated at the same time as the purging is interrupted for 3 sec. During this time the tank pressure is being observed.

Test 2
Enable criteria:
- Coolant Temperature when starting between 5-40 °C. The difference between the coolant temperature and intake air temperature is less than 5 °C. If the above conditions are not fulfilled a special test (warm start) will be carried out instead. (Test 3). Idling speed. Max. one change of status of the brake light switch. The volume of fuel in tank between 9-54 liters. Purging adaptation greater than -15%. Intake air pressure at least 20 kPa lower than the atmospheric pressure. The vehicle at a standstill for 5 sec. Battery voltage between 10-16 Volts. Tank pressure between -300 and 100 Pa.
The diagnosis will start once the above conditions have been fulfilled. If the diagnosis is interrupted then the speed must exceed 0 on one occasion before it is allowed to restart. The diagnosis continues then as follows: The shut-off valve is activated (closed) at the same time as any purging is interrupted for 4.5 sec. The tank pressure is observed, decreasing pressure reveals a leaking canister purge valve. Increasing pressure by more than 3 Pa/s indicates fuel evaporation, in these cases the diagnosis is repeated. If the pressure continues to rise by more than 3 Pa/s the diagnosis ceases. When the pressure increases less then 3 Pa/s Test 2 is complete.

Fault criteria
Test 1:
- If the pressure drops more than 40 Pa/s then an internal leakage in the canister purge valve has been detected.

Fault criteria
Test 2:
- If the pressure drops more than 27.5 Pa/s then an internal leakage in the canister purge valve has been detected. If the pressure increases by more than 3 Pa/s then there is major fuel evaporation, Test 2 will then be repeated. If it then continues to rise by more than 3 Pa/s the diagnosis ceases. To enable the diagnosis to be restarted the vehicle must be put in motion. When the pressure increases less than 3 Pa/s the diagnosis is complete.

Generating diagnostic trouble codes
- Diagnostic trouble codes P0441 and P1441 are generated when the fault criteria are fulfilled in Test 1 or Test 2 within the same driving cycle and dependents are OK.

Dependents:
- P0444, P0445, P0501, P0502, P0506, P0507, P1444, P1445, P1576 and P1577.

System reaction to a fault:
- None.

OK report:
- Test 1 or Test 2 performed once and fault criteria not fulfilled.

Fault handling: Fault Handling III, Other Emission-Related Component & Function
- Type III.

Diagnostic help
Fault diagnosis concerns a valve fault.
Functions in the diagnostic tool related to the fault:
- Diagnostic status for the diagnosis.
- Activate EVAP diagnosis.

For information, Tech 2 Menu Structure, DTC Menu, Read Value, Activate, Sys Info


NOTE: During the final check of a rectified fault, the diagnostic tool activation command must be used so that Test 1 is initiated irrespective of starting temperature.

Proceed to Diagnostic Procedures Initiating EVAP-Diagnostics