P0171, P0172

Read the instructions below then start the fault diagnostic procedure.

Symptom: CHECK ENGINE lamp on. Inferior driveability, unsteady idling speed. Possibly other diagnostic trouble codes (e.g. low fuel level, pressure sensor, closed loop, misfiring).

P0171, P0172

Fault symptoms

CHECK ENGINE lamp on. Inferior driveability, unsteady idling speed. Possibly other diagnostic trouble codes (e.g. low fuel level, pressure sensor, closed loop, misfiring).

Conditions

Ignition switch in ON position.

P0171: Adaptation >100 %

P0172: Adaptation <-100 %

Diagnostic help

If the adaptation fault has been caused by low fuel level, P1416 will also be generated.

Adaptation can be read with the diagnostic tool.

-	Select " Data Display".

-	Select " Multiplicative Adaptation".

Current adaptation ±100 % is shown.

Checking the wiring harness. Intermittent faults may occur in connection with short circuits and open circuits. Jiggle the wiring harness at several points and in several directions to locate any problems in the wiring, including intermediate connectors. Observe the multimeter, scan tool or test lamp during the check.