On-Board Diagnostics

Type of diagnosis: 

• Continuous. But interrupted when fault criteria fulfilled and will not restart until next driving cycle.

Enable criteria: 

• Engine running. Main relay voltage exceeding 10V. Output not active.

Fault criteria: 

• Output voltage below 2V. Criteria fulfilled for 10 periods that must occur during 60 s (normally, it takes 0.3 s for a trouble code to be generated but occasionally, it may take much longer).

Dependents: 

• None.

System reaction to a fault: 

• Air mass per combustion limited to 600 mg/c.

OK report: 

• As for P1549  : Engine running for longer than 60 sec. Charge air control valve PWM has exceeded 10 % on one occasion. Engine speed above 2500 RPM. Charge air control governing air mass per combustion. Current air mass per combustion differs less than 50 mg/c from requested. Or engine running for longer than 60 sec. Charge air control valve PWM has exceeded 10 % on one occasion. Engine speed 2000-3500 RPM. Requested air mass per combustion exceeding 650 mg/c. Throttle control governing air mass per combustion. Charge air pressure below 160 kPa. Current air mass per combustion differs less than 50 mg/c from requested.

Fault handling:  (For more information, see FAULT HANDLING III, OTHER EMISSION-RELATED COMPONENTS AND FUNCTION ).

• Type III.