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Home › Dodge and Ram › 2013 › Viper Base › Repair and Diagnosis › Engine Performance › System › 8.4L - DTCS P000B To P0175 › Diagnosis And Testing › P0138-O2 Sensor 1/2 Circuit High › Diagnostic Test

Diagnostic Test

  1. O2 SENSOR ABOVE 3.99 VOLTS 
    NOTE:

    When only one O2 Sensor is shorted to voltage, the scan tool will display all O2 Sensor voltage readings at approximately 5.0 volts. When diagnosing this DTC, only diagnose the O2 Sensor that set the DTC.

    1. Start the engine.
    2. Allow the engine to reach normal operating temperature.
    3. With a scan tool, read the O2 Sensor 1/2 voltage.

      Is the voltage above 3.99 volts?

      Yes 

      • Go To  2

      No 

  2. CHECK THE (K141) O2 1/2 SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE 
    1. Start the engine and allow the engine to idle.
    2. Disconnect the O2 Sensor 1/2 harness connector.
    3. Measure the voltage on the (K141) O2 Sensor 1/2 Signal circuit at the O2 Sensor 1/2 harness connector.
      NOTE:

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

      Is the voltage above 5.2 volts?

      Yes 

      • Repair the (K141) O2 Sensor 1/2 Signal circuit for a short to voltage.
      • Perform the PCM VERIFICATION TEST. Refer to STANDARD PROCEDURE .

      No 

      • Go To  3
  3. CHECK THE (K904) O2 1/2 RETURN CIRCUIT FOR A SHORT TO VOLTAGE 
    1. Measure the voltage on the (K904) O2 1/2 Return circuit in the O2 Sensor 1/2 harness connector.

      Is the voltage above 5.2 volts?

      Yes 

      • Repair the (K904) O2 1/2 Return circuit for a short to voltage.
      • Perform the PCM VERIFICATION TEST. Refer to STANDARD PROCEDURE .

      No 

      • Go To  4
  4. CHECK THE (K141) O2 1/2 SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. Turn the ignition off.
    2. Disconnect the PCM C1 harness connector.
    3. Measure the resistance of the (K141) O2 1/2 Signal circuit from the 1/2 O2 Sensor harness connector to the PCM C1 harness connector.

      Is the resistance below 5.0 Ohms?

      Yes 

      • Go To  5

      No 

      • Repair the (K141) O2 1/2 Signal circuit for an open or high resistance.
      • Perform the PCM VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  5. CHECK THE (K904) O2 1/2 RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. Measure the resistance of the (K904) O2 1/2 Return circuit from the O2 Sensor harness connector to the PCM C1 harness connector.

      Is the resistance below 5.0 ohms?

      Yes 

      • Go To  6

      No 

      • Repair the (K904) O2 1/2 Return Upstream circuit for an open or high resistance.
      • Perform the PCM VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  6. O2 SENSOR 
    1. Turn the ignition off.
    2. Reconnect the PCM C1 harness connector.
    3. Connect a jumper between the (K141) O2 1/2 Signal circuit and the (K904) O2 1/2 Return circuit at the O2 Sensor 1/2 harness connector.
    4. Turn the ignition on, engine not running.
    5. With a scan tool, monitor the O2 Sensor 1/2 voltage.

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

      Yes 

      No 

      • Go To  7
  7. POWERTRAIN CONTROL MODULE 
    NOTE:

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

    1. 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 

      No 

      • Replace and program the Powertrain Control Module in accordance with the service information.
      • Perform the PCM VERIFICATION TEST. Refer to STANDARD PROCEDURE .
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