(P0135) 02 Sensor 1/1 Heater Circuit High

(P0135) 02 SENSOR 1/1 HEATER CIRCUIT HIGH






When Monitored and Set Condition
^ When Monitored: Engine Running and Heater duty cycle greater than 0%.
^ Set Condition: 02 Heater Temperature does not reach 575 °C (959 °F) within 90 second during monitoring conditions. Two Trip Fault.

POSSIBLE CAUSES
02 HEATER ELEMENT
02 HEATER FUSED ENGINE CONTROL RELAY OUTPUT CIRCUIT OPEN
02 HEATER CONTROL CIRCUIT OPEN
POWERTRAIN CONTROL MODULE

Diagnostic Test
1. CHECK FOR CURRENT DTC





Note: If the PCM detects and stores a DTC, the PCM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the DRB III at the same time the DTC is displayed.

Note: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC. Turn the ignition on. With the DRB III, erase PCM DTCs.

Note: It maybe necessary to road test the vehicle for this DTC to set. With the DRB III, read the PCM DTCs.

Did this DTC set again?
Yes>> Go To 3
No>> Go To 2

2. 02 SENSOR HEATER OPERATION





Turn the ignition off.

Note: Allow the 02 Sensor to cool down before continuing the test. Raising the hood may help in reducing under hood temperatures.

Turn the ignition on.
With the DRB III, actuate the 02 Heater Test.
With the DRB III, monitor 02 Sensor voltage for at least 2 minutes.
Does the voltage stay above 0.47 volt?
Yes>> Go To 3
No>> Go To 6

3. 02 HEATER ELEMENT





Turn the ignition off.

Note: Allow the 02 Sensor to cool down to room temperature. Raising the hood may help in reducing under hood temperatures. Disconnect the 02 Sensor harness connector.

Note: Check connectors-Clean/repair as necessary. Measure the resistance of the 02 Sensor Heater element.

Note: 02 Sensor Heater Resistance Specification: 8.5 to 9.5 ohms.

Is the resistance within specifications?
Yes>> Go To 4
No>> Replace the 02 Sensor.
Perform Powertrain Verification Test - Ver 2

4. 02 HEATER FUSED ENGINE CONTROL RELAY OUTPUT CIRCUIT OPEN





Turn the ignition on.
Measure the voltage of the 02 Heater Fused Engine Control Relay Output circuit at the 02 Sensor harness connector.
Is the voltage above 10 volts?
Yes>> Go To 5
No>> Repair the 02 Heater Fused Engine Control Relay Output circuit for an open.
Perform Powertrain Verification Test - Ver 2

5. 02 HEATER CONTROL CIRCUIT OPEN





Turn the ignition off. Disconnect the PCM harness connectors.

Note: Check connectors-Clean/repair as necessary. Measure the resistance of the 02 Heater Control circuit from the 02 Sensor harness connector to the PCM harness connector.

Is the resistance below 5.0 ohms?
Yes>> Replace and program the Powertrain Control Module.
Perform Powertrain Verification Test - Ver 2
No>> Repair the 02 Heater Control circuit for an open.
Perform Powertrain Verification Test - Ver 2

6. INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.

Note: Check connectors-Clean/repair as necessary. Poor pin to terminal connections can set DTCs. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors specific to this DTC. Wiggle the wires while checking for shorts and open circuits.

Note: Check for any Technical Service Bulletins that may apply.

Were there any problems found?
Yes>> Repair as necessary.
Perform Powertrain Verification Test - Ver 2
No>> The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.