(P0135) 02 Sensor 1/1 Heater Circuit Low

(P0135) 02 SENSOR 1/1 HEATER CIRCUIT LOW






When Monitored and Set Condition
^ When Monitored: Engine Running and Heater duty cycle greater than 0%
^ Set Condition: The PCM detects the 02 Heater voltage is out of acceptable range. Below 0.0926 of a volt.

POSSIBLE CAUSES
02 HEATER CONTROL SHORTED TO GROUND
02 HEATER ELEMENT
POWERTRAIN CONTROL MODULE

Diagnostic Test
1. 02 HEATER ELEMENT





Note: Allow the 02 Sensor to cool down to room temperature.

Turn the ignition off.
Disconnect the 02 Sensor harness connector.

Note: Check connectors-Clean/repair as necessary.

Measure the resistance of the 02 Sensor Heater element at the 02 Sensor harness connector.
Is the 02 Sensor Heater element resistance between 8.5 and 9.5
ohms?
Yes>> Go To 2
No>> Replace the Oxygen Sensor.
Perform Powertrain Verification Test - Ver 2

2. 02 HEATER CONTROL CIRCUIT SHORTED TO GROUND





With the ignition off. Disconnect the PCM harness connectors.

Note: Check connectors-Clean/repair as necessary.

Measure the resistance between ground and the 02 Heater Control circuit.
Is the resistance below 100 ohms?
Yes>> Repair the 02 Heater Control circuit for a short to ground.
Perform Powertrain Verification Test - Ver 2
No>> Before continuing, check the PCM harness connector
terminals for corrosion, damage, or terminal push out.
Repair as necessary. Replace and program the Powertrain Control Module.
Perform Powertrain Verification Test - Ver 2