Generating Diagnostic Trouble Codes

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

  Fuel Level, plausibility diagnosis:  Because the fuel level is used as enable critera in certain diagnoses, the control module must know that the fuel level value is plausible. The way it works is that the Trionic receives a bus message "Fuel level XX litres" from the MIU. During driving the Trionic observes the value and as the car is driven, fuel is consumed. The Trionic makes sure the fuel level value drops. In the Trionic a number of important filtrations are carried out to avoid faults caused by for instance splashing fuel in the tank, starting uphill. The fuel level diagnosis can be called a support diagnosis as it does not generate a DTC, but if for instance the EVAP Purge valve diagnosis has reported a small leakage in the EVAP canister purge valve then DTC P0442 is normally generated. If on the other hand the tank integrity diagnosis has reported the same fault and the fuel level diagnosis has simultaneously reported a fault the DTC P1442 is generated instead.

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