Fault Isolation Procedure
- Checking the fault symptoms: If the customer has complained about the fuel gauge being faulty, go to next step. If DTC P0455 has been registered, go to step 4.
- Checking the DTCs in MIU:
- Contact MIU.
- Obtain readouts of DTCs: Main instrument unit.
If DTC B1720 has been stored, conduct fault diagnosis for trouble code B1720 (MIU), followed by diagnosis for P0455 (ECM). If the trouble code is not present, go to next step.
- Checking the fuel level sensor: Carefully check the connector and connections to the fuel level sensor in the wiring harness. If no faults are found, replace the fuel level sensor. go to next step.
- Diagnostic procedure: Check the evaporative emission system thoroughly for leaks. When finished, go to next step.
- Initiating EVAP-diagnostics:
- Activate EVAP-diagnostics.
- Follow the diagnostic tool's instructions.
- State what the diagnostic tool shows:
- OK - Inform the customer that the filler cap may not have been properly fitted. The steps taken to rectify the fault were correct. Clear the DTCs in all systems.
- NOT READY - The diagnosis has not yet been performed or has been cancelled. If the diagnosis has been cancelled, it can be restarted if the car is rolled a few meters and then stopped with the handbrake.
- P0442, P0455 - The diagnosis indicates that there is still a leak, continue to look for a leak.
Courtesy of SAAB-SCANIA OF AMERICA, INC.
Courtesy of SAAB-SCANIA OF AMERICA, INC.