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Home >> Jeep >> 2021 >> Grand Cherokee SRT >> Repair and Diagnosis >> Engine Performance >> System >> 6.4L - DTCS C053D To P0175 >> DTC Troubleshooting >> P0139-O2 Sensor 1/2 Slow Response >> Diagnostic Test
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Diagnostic Test

  1. ACTIVE DTC 
    NOTE:

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

    NOTE:

    After the repairs have been made, verify proper O2 Sensor operation. If all the O2 Sensor voltage readings have not returned to normal, follow the diagnostic procedure for the remaining O2 Sensors.

    1. Start the engine.
    2. Allow the engine to reach normal operating temperature.
      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 may result in possible serious or fatal injury.

    3. With the scan tool, select View DTCs.
      NOTE:

      It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data.

      Is the DTC Active or Pending at this time?

      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 

      • Repair or replace the leaking exhaust parts as necessary.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  3
  3. CHECK THE (K141) O2 SENSOR 1/2 SIGNAL CIRCUIT FOR PROPER VOLTAGE 
    GC0090690Courtesy of CHRYSLER GROUP, LLC
    1. Turn the ignition off
    2. Disconnect the O2 Sensor 1/2 Sensor harness connector.
    3. Ignition on, engine not running.
    4. Measure the voltage on the (K141) O2 Sensor 1/2 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 (K141) O2 Sensor 1/2 Signal circuit for a short to ground, open or short to voltage. If OK, 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 (K904) O2 SENSOR 1/2 RETURN CIRCUIT FOR PROPER VOLTAGE 
    GC0090691Courtesy of CHRYSLER GROUP, LLC
    1. Measure the voltage on the (K904) O2 Sensor 1/2 Return circuit in the O2 Sensor 1/2 harness connector.

      Is the voltage at 2.5 volts?

      Yes 

      • Go To  5

      No 

      • Check the (K904) O2 Sensor 1/2 Return circuit for a short to ground, open or short to voltage. If OK, replace and program the Powertrain Control Module in accordance with the Service Information.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  5. CHECK THE O2 SENSOR FOR PROPER OPERATION 
    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 Technical Service Bulletins that may apply.

      Were any problems found?

      Yes 

      No