Ho2S Heater(S)

DTC P1127 DETECTION CONDITION AND POSSIBLE CAUSE

DTC P1127	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 PII27 INSPECTION

STEP	INSPECTION		ACTION
1	KOER P1127 NGS Tester connected. 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 .