Mixture Adaption Factor FRA Bank 1 Drive Cycle C

DTC P0172
Mixture adaption factor FRA bank 1 Drive cycle C:Signal out of range - below minimum.

Possible causes by suggested order of priority:
^ Faulty injector (Low or high flow).
^ Fuel pressure regulator fault - pressure incorrect.
^ MAF sensor inaccurate.
^ Fuel pump fault - flow too low.
^ Part load breather pipe.

Faulty Injector (Low Or High Flow).
CHECK THE FOLLOWING:
^ Fuelling adaption FRA is normal on bank B (right)
^ There are no misfire faults set on the vehicle
^ There are no oxygen sensor or catalyst faults set on bank A (left).
^ Check Engine Roughness and misfire counts. Is one cylinder different from the others?
POSSIBLE FAULTS
^ Fuel injector flow rate too low (one injector bank A).
^ Fuel injector flow rate too high (one injector bank A).
DIAGNOSTIC SUGGESTIONS
^ Renew or temporarily substitute injector for any cylinder with abnormal engine roughness or misfire counts.
^ Renew or temporarily substitute all injectors for bank A.
^ Swap injectors with injectors from the opposite bank to see if fault can be transferred to opposite bank.

Fuel Pressure Regulator Fault - Pressure Incorrect.
CHECK THE FOLLOWING:
^ Fuelling adaption FRA is also abnormal on bank B (right).
^ There are no misfire faults set on the vehicle.
^ There are no oxygen sensor or catalyst faults set.
POSSIBLE FAULTS
^ Fuel pressure too low (high FRA adaption).
^ Fuel pressure too high (low FRA adaption).
DIAGNOSTIC SUGGESTIONS
^ Fit fuel pressure gauge and measure fuel pressure.

MAF Sensor Inaccurate.
CHECK THE FOLLOWING:
^ Fuelling adaption FRA is also abnormal on bank B (right).
^ There are no misfire faults set on the vehicle.
^ There are no oxygen sensor or catalyst faults set.
^ Fuel pressure (measured with pressure gauge) is correct.
POSSIBLE FAULTS
^ MAF sensor is functioning but inaccurate.
DIAGNOSTIC HINTS
^ Renew MAFS or test by substitution with known good unit.

Fuel Pump Fault - Flow Too Low.
CHECK THE FOLLOWING:
^ Fuelling adaption FRA is abnormally high on both banks.
^ There are no misfire faults set on the vehicle.
^ There are no oxygen sensor or catalyst faults set.
POSSIBLE FAULTS
^ Fuel pressure too low at high engine power due to poor fuel pump flow.
DIAGNOSTIC SUGGESTIONS
^ Fit fuel pressure gauge and measure fuel pressure during driving at high engine revs.

Part Load Breather Pipe.
CHECK THE FOLLOWING:
^ Part load breather pipe connections.
^ State of the part load breather pipe for cracks etc.