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Home >> Jeep >> 2023 >> Compass Red >> Repair and Diagnosis >> Engine Performance >> System >> 2.0L - DTCS P0117 To P018C >> DTC Troubleshooting >> P0140-O2 Sensor 1/2 Signal Inactive >> Diagnostic Test
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Diagnostic Test

  1. CHECK FOR ANY SERVICE BULLETINS OR PCM SOFTWARE UPDATES 
    1. Check for any applicable Service Bulletins or Flash updates related to the DTC.

      Are there any applicable Service Bulletins or Flash updates?

      Yes 

      No 

      • Go To  2
  2. READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR THE DTC TO RETURN 
    1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
    2. For future reference, with the scan tool, run and save a vehicle Scan Report and all related recorded data.
    3. With the scan tool, erase all DTCs.
    4. Turn the ignition off for a minimum of 10.0 seconds.
    5. Turn the ignition on.
    6. Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
    7. With the scan tool, read DTCs.

    Did the DTC return?

    Yes 

    • Go To  3

    No 

  3. CHECK FOR OTHER DTCS 
    1. Refer to the recorded DTCs.

      Are there any O2 Sensor circuit DTCs also present?

      Yes 

      No 

      • Go To  4
  4. CHECK 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  5
  5. CHECK THE O2 SENSOR MOUNTING AND WIRING HARNESS CONNECTOR 
    1. Using the appropriate SYSTEM WIRING DIAGRAM/schematic as a guide, inspect the wiring and connectors between the O2 Sensor 1/2 and the Powertrain Control Module (PCM).
      • Check the O2 Sensor for proper mounting. Verify the sensor is not loose or cross threaded, or that the boss is not damaged.
      • 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.

      Were any problems found?

      Yes 

      No 

      • Replace the Oxygen Sensor 1/2 in accordance with the Service Information. Refer to ENGINE SENSORS, REMOVAL AND INSTALLATION .
        NOTE:

        Check for signs of contaminants that may have damaged the O2 Sensor, such as contaminated fuel, unapproved silicone, oil and coolant and perform the appropriate repairs before replacing the O2 Sensor.

      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .