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P0455

Read the instructions below then start the fault diagnostic procedure.

Symptom: CHECK ENGINE comes on after two driving cycles.Possible smell of petrol.

P0455

EVAP. Serious Leakage in System.





For a diagnostic trouble code to be set, the cold start diagnosis and then the regular diagnosis must first be performed. The engine coolant temperature must be below 40°C (104°F) when the engine is started to achieve this. A diagnostic trouble code can therefore not be generated if the engine is warm when started.

To perform a final check of a rectified fault, use the diagnostic tool's actuating commando so that the cold start test will be 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




Diagnosis not yet performed during this driving cycle.

Diagnosis commenced more than 8 times during this driving cycle.

Engine coolant temperature below 40°C (104°F) when engine was started.

Idling speed.

Car stationary for more than 5 sec.

Max. one change of status of the brake light switch.

Additional fuel from purge is less than 7%% of the engine's fuel requirements.


When the conditions above have been fulfilled, the diagnosis will start by closing the shut-off valve and setting the PWM of the EVAP canister purge valve 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




Tank pressure cannot be lowered by 0.6 kPa within 23 sec.


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




Conditions for cold start diagnosis not fulfilled during this driving cycle or cold start diagnosis indicated a leak.

Diagnosis commenced more than 8 times during this driving cycle.

Approved transition diagnosis of oxygen sensor 1.

The PWM of the EVAP canister purge valve has exceeded 40%% at some time.

Idling speed.

Car stationary for more than 5 sec.

Max. one change of status of the brake light switch.

Additional fuel from purge is less than 7%% of the engine's fuel requirements.


When the conditions above have been fulfilled, the diagnosis will start by closing the shut-off valve and setting the PWM of the EVAP canister purge valve to 15%%. The additional fuel from the purge is allowed to be 13%% of that required by the engine.

Fault criteria for the regular diagnosis




Tank pressure cannot be lowered by 0.6 kPa within 23 sec.


Diagnostic help

Fault diagnosis starts by checking the electrical function of the EVAP canister purge valve and the shut-off valve. If these are OK, leak detection is carried out. After fault diagnosis and diagnostic procedure have been performed, a final check is carried out when the cold start diagnosis is initiated. The diagnostics tool indicates whether there is a leak or not.

Diagnostic tool functions related to this fault are:


Tank pressure, unit kPa.

Actuating the EVAP canister purge valve.

Actuating the EVAP shut-off valve.

Actuating EVAP diagnosis.


The cold start 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 evaporative emission canister is saturated, it may be difficult to perform the diagnosis as the additional fuel from the purge is then often more than 7%% of the engine's fuel requirements.

Check the wiring

Jiggle the leads and in-line connectors at various points and in different directions to detect any intermittent breaks or short circuits in the wiring. Observe the multimeter, test lamp or diagnostic tool while doing this.