Ho2S Heater (S)

DTC P1127 DETECTION CONDITION & POSSIBLE CAUSES

DTC P1127	HEATED OXYGEN SENSOR (HO2S) HEATER(S)
DETECTION CONDITION	P1127 indicates that the inferred exhaust temperature to determine when HO2S heaters are cycled on is below a minimum calibrated value.
POSSIBLE CAUSE	Engine not operating long enough prior to performing KOER self-test Exhaust system too cool

DTC P1127 DIAGNOSTIC PROCEDURE

DTC P1127		HO2S HEATER(S)
STEP	INSPECTION		ACTION
1	KOER P1127 Connect WDS or equivalent tester. Key on, engine off (KOEO). Access the following PIDs. HTR11 (front RH) HTR21 (front LH) HTR12 (rear) Key OFF. Do all PIDs Indicate ON?	Yes	Engine still operating. Perform KOER self-test. See ON - BOARD DIAGNOSTIC TESTS .
1		No	Operate the engine until all PIDs indicate ON. Perform KOER self-test. See ON - BOARD DIAGNOSTIC TESTS .