P0158

P0158-O2 SENSOR 2/2 CIRCUIT HIGH





For a complete wiring diagram refer to Diagrams/Electrical.


- When Monitored:

Continuously with the engine running, no O2 sensor heater DTCs present, 2/2 Oxygen Sensor heater temperature within a specific range, and battery voltage greater than 10.4 volts.

- Set Condition:

The PCM detects that the 2/2 Oxygen Sensor voltage is greater than the maximum acceptable value for a specific amount of time, based on O2 sensor heater temperature. The DTC will set as Pending after one trip and Active after two trips. Three good trips to turn off the MIL.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.


Diagnostic Test


1. ACTIVE DTC


NOTE: If an O2 sensor signal circuit is shorted to voltage, all O2 sensor voltage readings displayed on the scan tool will beapproximately 5.0 volts. Diagnose the sensor that set the most current DTC.

Start the engine and allow it to idle for at least 60 seconds.


WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

With a scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition


2. (K243) O2 2/2 SIGNAL CIRCUIT SHORTED TO VOLTAGE





Turn the ignition off.

Disconnect the C1 PCM harness connector.

Disconnect the 2/2 O2 Sensor harness connector.

Turn the ignition on.

Measure the voltage on the (K243) O2 Sensor 2/2 Signal circuit in the O2 Sensor harness connector.


NOTE: Measure the voltage in reference to ground, not the (K904) O2 Return Downstream circuit.

Is there any voltage present?

Yes

- Repair the short to voltage in the (K243) O2 Sensor 2/2 Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 3


3. (K904) O2 RETURN DOWNSTREAM CIRCUIT SHORTED TO VOLTAGE





Measure the voltage on the (K904) O2 Return Downstream circuit in the 2/2 O2 Sensor harness connector.

Is there any voltage present?

Yes

- Repair the short to battery voltage in the (K904) O2 Return Downstream circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 4


4. O2 SENSOR





Turn the ignition off.

Connect the C1 PCM harness connector.

Ignition on, engine not running.

With a scan tool, monitor the 2/2 O2 Sensor voltage.

Connect a jumper wire between the (K243) O2 2/2 Signal circuit and the (K904) O2 Return Downstream circuit in the 2/2 O2 Sensor harness connector.

Is the voltage between 2.3 and 2.7 volts with the jumper wire installed?

Yes

- Replace the O2 Sensor.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 5

NOTE: Remove the jumper wire before continuing.


5. (K243) O2 2/2 SIGNAL CIRCUIT OPEN





Turn the ignition off.

Disconnect the C1 PCM harness connector.


CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

Measure the resistance of the (K243) O2 2/2 Signal circuit from the O2 Sensor harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes

- Go To 6

No

- Repair the open in the (K243) O2 2/2 Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test


6. (K904) O2 RETURN DOWNSTREAM CIRCUIT OPEN





Measure the resistance of the (K904) O2 Return Downstream circuit from the O2 Sensor harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes

- Go To 7

No

- Repair the open in the (K904) O2 Return Downstream circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test


7. PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Replace and program the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test