P1171 , P1172

Read the instructions below then start the fault diagnostic procedure.

Symptom: CHECK ENGINE lamp on. Possible other diagnostic trouble codes (low fuel level, misfiring, oxygen sensor, pressure sensor)

P1171 , P1172

Fault symptoms

CHECK ENGINE lamp on. Possible other diagnostic trouble codes (low fuel level, misfiring, oxygen sensor, pressure sensor)

Conditions

•	Global adaptation performed during the driving cycle

•	Closed loop active.

P1171: Closed loop >25 % for longer than 20 sec.

P1172: Closed loop <-25 % for longer than 20 sec.

Diagnostic help

If the closed loop fault is due to low fuel level, this will be indicated by diagnostic trouble code P1416 also being generated. Closed loop can be read with the diagnostic tool.

-	Select " Data Display / Output Control (New)".

-	Select " Short Term Fuel Trim".

Current closed loop ±25 % is shown.

. 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.