P0135

Tests 1 - 3:

Tests 4 - 7:

Test 8:

SYMPTOM
P0135-1/1 O2 SENSOR HEATER FAILURE

WHEN MONITORED
With battery voltage greater than 10.5 volts, at a cold start, ECT less than 147 °F, battery temperature sensor equal to or less than 27 °F, and engine at idle for at least 12 seconds.

SET CONDITION
O2 Sensor voltage greater than 3 volts for 30 to 90 seconds.

POSSIBLE CAUSES
- Intermittent condition
- Heater element check
- O2 Sensor heater supply circuit open
- O2 Sensor heater ground circuit open
- PWM circuit open
- O2 Sensor heater control circuit shorted to ground
- PCM