P0158

P0158-O2 SENSOR 2/2 CIRCUIT HIGH





For a complete wiring diagram Consult Diagrams/Electrical.

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

- Set Condition:
The PCM detects that the 2/2 O2 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. Initial Inspection and Diagnostic Overview.

Diagnostic Test

1. 2/2 O2 SENSOR VOLTAGE

NOTE: If an O2 sensor signal circuit is shorted to voltage, all O2 sensor voltage readings displayed on the scan tool will be approximately 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 *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure.Checking For An Intermittent DTC

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




Turn the ignition off.
Disconnect the 2/2 O2 Sensor harness connector.
Disconnect the Powertrain Control Module (PCM) harness connector.
Turn the ignition on.
Measure the voltage of the (K243) O2 2/2 Signal circuit in the 2/2 O2 Sensor harness connector.

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

Is there any voltage present?

Yes

- Repair the (K243) O2 2/2 Signal circuit for a short to voltage.
- Perform the PCM Verification Test.Powertrain Verification Test

No

- Go to 3

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




Measure the voltage on the (K904) O2 Return (Down) circuit in the 2/2 O2 Sensor harness connector.
Is there any voltage present?

Yes

- Repair the (K904) O2 Return (Down) circuit for a short to voltage.
- Perform the PCM Verification Test.Powertrain Verification Test

No

- Go to 4

4. (K243) O2 2/2 SIGNAL CIRCUIT SHORTED TO THE (K399) O2 2/2 HEATER CONTROL CIRCUIT




Turn the ignition off.
Measure the resistance between the (K243) O2 2/2 Signal circuit and the (K399) O2 2/2 Heater Control circuit the 2/2 O2 Sensor harness connector.
Is the resistance below 100.0 ohms?

Yes

- Repair the (K243) O2 2/2 Signal circuit for a short to the (K399) O2 2/2 Heater Control circuit.
- Perform the PCM Verification Test.Powertrain Verification Test

No

- Go to 5

5. 2/2 O2 SENSOR




Turn the ignition off.
Connect the Powertrain Control Module (PCM) harness connector.
Connect a jumper wire between the (K243) O2 2/2 Signal circuit and the (K904) O2 Return (Down) circuit in the 2/2 O2 Sensor harness connector.
Turn the ignition on.
With a scan tool, monitor the 2/2 O2 Sensor voltage.
Is the voltage between 2.3 and 2.7 volts with the jumper wire in place?

Yes

- Replace the 2/2 O2 Sensor.
- Perform the PCM Verification Test.Powertrain Verification Test

No

- Go to 6

6. (K243) O2 2/2 SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE




Turn the ignition off.
If necessary, remove the jumper wire from between the (K243) O2 2/2 Signal circuit and the (K904) O2 Return (Down) circuit in the 2/2 O2 Sensor harness connector.
Disconnect the Powertrain Control Module (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 between the 2/2 O2 Sensor harness connector and the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?

Yes

- Go to 7

No

- Repair the (K243) O2 2/2 Signal circuit for an open circuit or high resistance.
- Perform the PCM Verification Test.Powertrain Verification Test

7. (K904) O2 RETURN (DOWN) CIRCUIT OPEN OR HIGH RESISTANCE




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 (K904) O2 Return (Down) circuit between the 2/2 O2 Sensor harness connector and the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?

Yes

- Go to 8

No

- Repair the (K904) O2 Return (Down) circuit for an open circuit or high resistance.
- Perform the PCM Verification Test.Powertrain Verification Test

8. POWERTRAIN CONTROL MODULE (PCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the 2/2 O2 Sensor and the Powertrain Control Module (PCM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Search for any Technical Service Bulletins that may apply.
Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM Verification Test.Powertrain Verification Test

No

- Replace and program the Powertrain Control Module (PCM).
- Perform the PCM Verification Test.Powertrain Verification Test