P0171 : System Too Lean (Bank 1)

[Hystérique]

Par oû devrais-je commencer par me salir les mains ou le nez?

[rj240]

284: ECM-250A Long-term fuel trim. Lower limit, B5244S

Diagnostic trouble code (DTC) information ECM-250A

Condition
The engine control module (ECM) receives information from the heated oxygen sensor (HO2S) about the fuel/air mixture at different loads. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the fuel/air mixture deviates too much from target lambda value, leaving the long-term trim in one of its limit positions.

Substitute value
None.

Possible source

Lower limit:
Damaged mass air flow (MAF) sensor
High fuel pressure
Leaking injectors
Leaking evaporative emission system (EVAP)
Contaminated engine oil
Oil level too high.

Fault symptom[s]
Malfunction indicator lamp (MIL) lit
Poor performance
May result in high fuel consumption.