DTC P1127: Notes

DTC P1127 (MZI-3.5) DETECTION CONDITION AND POSSIBLE CAUSES

DTC P1127	Exhaust temperature out of range, HO2S tests not completed
DETECTION CONDITION	The HO2S monitor uses an exhaust temperature model to determine when the HO2S heaters are cycled ON. The test fails when the inferred exhaust temperature is below a minimum calibrated value.
POSSIBLE CAUSE	Engine not operating long enough prior to carrying out the KOER self-test Exhaust system too cool