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Home >> Chrysler >> 2018 >> 300 C >> Repair and Diagnosis >> Engine Performance >> System >> 5.7L - DTCS P000B To P0197 >> DTC Troubleshooting >> P0139-O2 Sensor 1/2 Slow Response >> Diagnostic Test
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Diagnostic Test

  1. CHECK FOR AN ACTIVE DTC 
    NOTE:

    Check for contaminants that may have damaged the O2 Sensor: contaminated fuel, unapproved silicone, oil and coolant.

    1. Start the engine and test drive the vehicle.
    2. With the scan tool, read DTCs.

      Is the DTC active or pending?

      Yes 

      • Go To  2

      No 

  2. CHECKING THE EXHAUST SYSTEM FOR LEAKS 
    1. Perform the CHECKING THE EXHAUST SYSTEM FOR LEAKS test procedure. Refer to CHECKING THE EXHAUST SYSTEM FOR LEAKS .

      Were any exhaust leaks found?

      Yes 

      No 

      • Go To  3
  3. CHECK THE O2 SENSOR 1/2 (K141) SIGNAL CIRCUIT 
    1. Turn the ignition off
    2. Disconnect the O2 Sensor 1/2 Sensor harness connector.
    3. Turn the ignition on.
    4. Measure the voltage between ground and the O2 Sensor 1/2 (K141) Signal circuit in the O2 Sensor 1/2 harness connector.

      Is the voltage between 4.1 and 5.0 volts?

      Yes 

      • Go To  4

      No 

      • Check the O2 Sensor 1/2 (K141) Signal circuit for a short to ground, open or short to voltage. If no problems are found, replace and program the Powertrain Control Module in accordance with the Service Information.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  4. CHECK THE O2 SENSOR 1/2 (K904) RETURN CIRCUIT 
    1. Measure the voltage between ground and the O2 Sensor 1/2 (K904) Return circuit in the O2 Sensor 1/2 harness connector.

      Is the voltage at 2.5 volts?

      Yes 

      • Go To  5

      No 

      • Check the O2 Sensor 1/2 (K904) Return circuit for a short to ground, open or short to voltage. If no problems are found, replace and program the Powertrain Control Module in accordance with the Service Information.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  5. O2 SENSOR 
    NOTE:

    Check for signs of contaminants that may have damaged the O2 Sensor 1/2, such as contaminated fuel, unapproved silicone, oil and coolant.

    1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the O2 Sensor 1/2 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.
      • Verify that there is good pin to terminal contact in the O2 Sensor 1/2 and Powertrain Control Module connectors.
      • Perform any Service Bulletins that may apply.

      Were any problems found?

      Yes 

      No