P0135

Tests 1 - 5:

Tests 6 - 10:

Tests 11 - 13:

SYMPTOM
P0135 - 1/1 O2 SENSOR HEATER FAILURE

WHEN MONITORED
With battery voltage greater than 9 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
- Open fuse
- O2 sensor heater feed circuit open
- O2 sensor heater ground circuit open
- O2 sensor relay
- Fused B+ output circuit open
- O2 sensor heater relay output circuit open
- Short to ground between relay and fuse
- Wiring harness intermittent problem
- O2 sensor