P0442
Read the instructions below then
start the fault diagnostic procedure.
Symptom: CHECK ENGINE comes on after two driving cycles.
Possible smell of petrol.
EVAP. Small Leakage in System.
Before this DTC can be set, the cold start diagnosis must first be carried out and then the ordinary diagnosis. The engine coolant temperature must be below 40°C (104°F) when the engine is started, to achieve this. A DTC can therefore
not
be generated if the engine is warm when started.
To perform a final check on a rectified fault, use the activating command on the diagnostics tool so that the cold start test is performed irrespective of the starting temperature.
Fault symptoms
CHECK ENGINE comes on after two driving cycles.
Possible smell of petrol.
Conditions for cold start diagnosis
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Diagnosis not yet performed during this driving cycle.
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Diagnosis commenced more than 8 times during this driving cycle.
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Engine coolant temperature below 40°C (104°F) when engine was started.
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Car stationary for more than 5 s.
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Max. one change of status of the brake light switch.
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Additional fuel from purge is less than 7 % of the engine's fuel requirements.
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When the conditions above are fulfilled, the diagnosis will start by closing the shut-off valve and setting the purge valve PWM to 15 %. The additional fuel from the purge is allowed to be 13 % of that required by the engine.
Fault criteria for cold start diagnosis
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Tank pressure reduced by 0.6 kPa within 23 s.
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When the purge is later interrupted, the pressure rises by more than 0.3 kPa within 9 s.
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If the diagnosis is interrupted, the vehicle speed must exceed 4 km/h (2.5 mph) on one occasion before the diagnosis can be restarted.
If the cold start diagnosis indicates a leak, the shut-off valve is activated 4 times in quick succession to remove any contamination present on the sealing surfaces of the valve.
Conditions for the regular diagnosis
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Conditions for cold start diagnosis not fulfilled during this driving cycle or cold start diagnosis indicated a leak.
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Diagnosis commenced more than 8 times during this driving cycle.
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Approved transition diagnosis of oxygen sensor 1.
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The purge valve PWM has exceeded 40 % at some time.
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Car stationary for more than 5 s.
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Max. one change of status of the brake light switch.
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Additional fuel from purge is less than 7 % of the engine's fuel requirements.
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When the conditions above are fulfilled, the diagnosis will start by closing the shut-off valve and setting the purge valve PWM to 15 %. The additional fuel from the purge is allowed to be 13 % of that required by the engine.
Fault criteria for the ordinary diagnosis
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Tank pressure reduced by 0.6 kPa within 23 s.
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When the purge is later interrupted, the pressure rises by more than 0.3 kPa within 9 s.
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Diagnostic help
Fault diagnosis starts with leak detection. After fault diagnosis and diagnostic procedure, a final check is made when the cold start diagnosis is initiated. The diagnostic tool indicates whether or not there is a leak in the system.
Diagnostic tool functions related to this fault are:
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Select "
Data Display / Output Control (New)" and "
Tank Pressure".
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Activate "
EVAP Diagnosis".
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The cold start diagnosis can be initiated with the diagnostic tool irrespective of what the coolant temperature was when the engine was started. At high temperatures and when the EVAP canister is saturated, it may be difficult to carry out the diagnosis as the additional fuel from the purge is then often more than 7 % of the engine's fuel requirements.
