P0155

Tests 346 - 350:

Tests 351 - 352:

SYMPTOM
P-0155 2/1 O2S HEATER FAILURE

WHEN MONITORED
With the engine at idle immediately after a cold start (engine < 147 degrees F and battery temp ± 27 degrees F of engine temperature.

SET CONDITION
O2 sensor voltage > 3V for 30 to 90 seconds.

POSSIBLE CAUSES
- 2/1 O2 sensor connector damaged
- 2/1 O2 sensor gnd circuit open
- ASD relay output circuit open
- 2/1 O2 sensor failure
- 2/1 O2 sensor heater element failure
- 2/1 O2S heater failure does not reoccur