P1442

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

Idling. Max. one change in status of brake light switch. Fuel volume in tank between 11-54 litres. Purging adaptation higher than -15%. Intake air pressure at least 20 kPa lower than the atmospheric pressure. The vehicle stationary for 5 sec. Battery voltage between 10-16 Volts. Tank pressure between -300 to +100 Pa.

The diagnosis will start once the above conditions have been fulfilled for 5 seconds. If the diagnosis is interrupted then the speed must exceed 0 on one occasion before it is allowed to restart. 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 possible purging is stopped for 4.5 sec. Tank pressure is observed, falling pressure reveals leaks in purging valve. Rising pressure of more than 3 Pa/s points to fuel evaporation, in these cases Phase A is repeated. If it becomes apparent that the pressure is rising by more than 3 Pa/s the diagnosis is interrupted, vehicle speed is needed during a certain time for it to be restarted. For pressure increases less than 3 Pa/s then Phase A is complete. The diagnosis continues to Phase B (pressure reduction)

Phase B) Pressure reduction Shut-off valve is still closed, the purging valve's pulse ratio is set at 23-24.5%. If the diagnosis is terminated, the speed must exceed 0 on one occasion before it is allowed to restart. 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 possible purging is stopped for 4.5 sec. Tank pressure is observed, falling pressure reveals leaks in purging valve. Rising pressure of more than 4 Pa/s points to fuel evaporation, in these cases Phase A is repeated. If it becomes apparent that the pressure is rising by more than 4 Pa/s the diagnosis is interrupted, vehicle speed is needed during a certain time for it to be restarted. For pressure increases less than 4 Pa/s then Phase A is complete. The diagnosis continues to Phase B (pressure reduction)

Phase B) Pressure reduction Shut-off valve is still closed, the purging valve's pulse ratio is set at 18% until the tank pressure has reached -600 Pa. This pressure reduction should take no more than max. 30 seconds.

Phase C) Pressure retention The shut-off valve is still closed, the purging valve is closed. The tank pressure is observed for max. 12 seconds.

Fuel level, Plausibility diagnosis: Because fuel level is used as an enable criteria in certain diagnosis, then the control module must know that fuel level value is plausible. It works in such a way that Trionic receives the bus message ”Fuel level XX litre" from MIU. While driving Trionic observes the value and as the vehicle is driving it is consuming petrol, Trionic sees that the fuel level value will fall. In Trionic there is a number of filtrations of the value so as to avoid inaccuracies due to for example splashing fuel in the tank and hill starts. The fuel level diagnosis can be said to be a support diagnosis, it does not generate its own diagnostic trouble codes, but if for example the EVAP valve diagnosis has reported a small leakage in the purging valve then DTC P0442 is normally generated. If on the other hand the integrity diagnosis has reported the same fault and the fuel level diagnosis at the same time has also reported a fault then DTC P1442 is generated instead.

In addition for Test 2 (Warm start), the intake air temperature has not been below 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

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