P0135

Tests 1 - 2:

Tests 3 - 6:

Test 7:

SYMPTOM
P0135 - /1 O2 SENSOR HEATER FAILURE

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

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

POSSIBLE CAUSES
- 1/1 O2 sensor connector
- 1/1 O2 sensor ground circuit open
- ASD relay output circuit open
- 1/1 O2 sensor failure
- 1/1 O2 sensor heater element failure
- 1/1 O2 sensor heater failure does not reoccur