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P0442

Read the instructions below then start the fault diagnostic procedure.

Symptom: CHECK ENGINE. Possible smell of petrol.

P0442


EVAP. Small Leakage in System.


Fault symptoms


• CHECK ENGINE.

• Possible smell of petrol.


On-Board Diagnostics

Type of diagnosis:


- Once per driving cycle. Interrupted when fault criteria fulfilled or OK reported. Restarts next driving cycle.


Test 1, Cold start

Enable criteria


- Coolant Temperature when starting is between 5-40°C. The difference between coolant temperature and intake air temperature is less then 5°C.

If the above conditions are not fulfilled, Test 2 (warm start) will start.

Idling speed. Max. one change of status of the brake light switch. Purging adaptation higher than -15%. Intake air pressure at least 20 kPa lower than the barometric pressure. Vehicle at a standstill for 5 seconds. The volume of fuel in tank between 9-54 litres. Battery voltage between 10-16 volts. Tank pressure between -300 and +100 Pa.

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 at one stage before the diagnosis is allowed to be restarted. The diagnosis is divided in three phases, A-C:

Phase A) Evaporation check 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 hints at fuel evaporation, in these cases Phase A should be repeated. If it then continues to rise by more than 3 Pa/s quit the diagnosis. To be able to continue, vehicle speed is required for a short time. When the pressure increases less then 3 Pa/s Phase A is complete. The diagnosis continues to Phase B (pressure decrease)

Phase B) Pressure decrease Shut-off valve is still closed, canister purge valve pulse ratio is set to 23-24.5% until the tank pressure has reached -600 Pa. This decrease in pressure should take Max. 30 sec.

Phase C) Maintaining pressure The shut-off valve is still closed, canister purge valve is closed. The tank pressure is observed for max. 12 sec.


Test 2, warm start

Enable criteria


- The following conditions should be fulfilled within 5 sec. to be able to start the diagnosis: Coolant Temperature and inlet air temperature when starting exceeding +40°C and the difference between coolant temperature and inlet air temperature greater than 5°C.

Idling speed. Max. one change of status of the brake light switch. Purging adaptation higher than -6%. Tank pressure between -300 and +100 Pa. Inlet air pressure at least 20 kPa lower than the atmospheric pressure. The vehicle stationery.The volume of fuel in the tank 9-54 litres. Battery voltage between 10-16 Volts. Tank pressure sensor diagnosis should report OK.

When the above condition is fulfilled for more than 5 sec. the diagnosis will start. The diagnosis will be interrupted if the purging adaptation exceeds -8%. Should the diagnosis be interrupted the speed must exceed 0 at one stage before the diagnosis is allowed to be restarted. The diagnosis is divided into three phases, A-C:

Phase A) Evaporation check 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 4 Pa/s hints at fuel evaporation, in these cases Phase A should be repeated. If it then continues to rise by more than 4 Pa/s quit the diagnosis. To be able to continue, vehicle speed is required for a short time. When the pressure increases less then 4 Pa/s Phase A is complete. The diagnosis continues to Phase B (pressure decrease)

Phase B) Pressure decrease Shut-off valve is still closed, canister purge valve pulse ratio is set to 18% until the tank pressure has reached -600 Pa. This decrease in pressure should take Max. 30 sec.

Phase C) Maintaining pressure The shut-off valve is still closed, canister purge valve is closed. The tank pressure is observed for max. 12 sec.


Fault criteria

Test 1, Cold start


- Phase A) Evaporation check If the pressure decreases by 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 you have major fuel evaporation, in these cases Phase A should be repeated. If it then continues to rise by more than 3 Pa/s quit the diagnosis. 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 should continue to Phase B.

- Phase B) Pressure decrease If the pressure cannot be decreased to -450 Pa within 15 seconds or if the pressure reaches -450 Pa within 15 seconds but not as low as -600 Pa within a further 15 seconds (total 30 sec.) then a major leakage has been found.

- Phase C) Maintaining pressure If the pressure increases to -450 Pa within 12 seconds then a small leakage has been found.


Fault criteria

Test 2, warm start


- Phase A) Evaporation check If the pressure decreases by 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 4 Pa/s then you have major fuel evaporation, in these cases Phase A should be repeated. If it then continues to rise by more than 4 Pa/s quit the diagnosis. To enable the diagnosis to be restarted the vehicle must be put in motion. When the pressure increases less than 4 Pa/s the diagnosis should continue to Phase B.

- Phase B) Pressure decrease If the pressure cannot be decreased to -450 Pa within 15 seconds or if the pressure reaches -450 Pa within 15 seconds but not as low as -600 Pa within a further 15 seconds (total 30 sec.) then a major leakage has been found.

- Phase C) Maintaining pressure If the pressure increases to -450 Pa within 12 seconds then a small leakage has been found.


Generating diagnostic trouble codes


- Diagnostic Trouble Codes are generated when the above fault criteria are fulfilled and the dependants are OK.

In Test 2 (warm start) intake air temperature should also not have been lower than 5°C.

P0441, P1441 are generated if faults are reported during Phase A

P0455, P1455 are generated if faults are reported during Phase B

P0442 , P1442 are generated if faults are reported during Phase C


Dependents


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


OK report


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

Note

Diagnostic trouble codes P0442, P0455, P1442 and P1455 are cleared directly after OK report from the diagnosis.



Fault handling

(For more information, see .)


- Type III.


Diagnostic help

Fault diagnosis concerns a leak.

Functions in the diagnostic tool related to the fault:


• Diagnostic status for the diagnosis.

• Activating EVAP diagnosis.


For more information, see .

Note

For a final check of the faults that have been taken care of, the diagnostic tool activating command should be used when Test 1 (cold start) is initiated regardless of the starting temperature.