Diagnostic Test

WARNING: This page is about a different car, the 2024 Jeep Grand Wagoneer L and 2024 Jeep Grand Wagoneer. However, it is still accessible from the selected car via links, so may be relevant.

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 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
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
  - Perform the applicable repair.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK FOR OTHER DTCS
1. Refer to the recorded DTCs.
  NOTE:
  Any O2 Sensor heater or signal circuit DTCs should be diagnosed before continuing with this procedure.
  
  Are there any O2 Sensor heater or signal circuit DTCs present?
  
  Yes
  - Perform the applicable diagnostic procedure(s). Refer to DIAGNOSTIC CODE INDEX .
  No
  - Go To 4
CHECK THE INTAKE SYSTEM AND AIR FILTER FOR RESTRICTIONS OR BLOCKAGE
1. Check for a blockage in the intake air system plumbing.
2. Visually inspect the Air Filter for a restriction.
  NOTE:
  Poor airflow due to a severely restricted Air Filter can cause this DTC to set.
  
  Were any issues found?
  
  Yes
  - Replace the Air Filter or repair the blockage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
CHECK THE O2 SENSOR FOR PROPER MOUNTING
1. Check and verify that the Upstream O2 Sensor is mounted correctly into the exhaust. Verify the sensor is tight and not cross threaded.
  Is the O2 Sensor mounted correctly?
  
  Yes
  - Go To 6
  No
  - Mount the O2 Sensor correctly.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE O2 SENSOR 1/1 CONNECTOR AND TERMINALS
1. Turn the ignition off.
2. Check the O2 Sensor 1/1 harness connector for proper connection at the O2 Sensor.
3. Verify that the connector is completely plugged in and properly locked prior to disconnecting.
4. Disconnect the O2 Sensor 1/1 harness connector and check for any pushed out, damaged or spread terminals.
  Were any issues found with the connector or terminals?
  
  Yes
  - Repair the damaged terminal or properly connect and lock the O2 Sensor 1/1 harness connector and retest for DTCs.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 7
CHECK THE ORIENTATION OF THE UPSTREAM AND DOWNSTREAM O2 SENSOR HARNESS CONNECTORS
1. Check and verify that the Upstream O2 Sensor and Downstream O2 Sensor harness connectors are properly connected to the correct sensors.
  Are the harness connectors reversed?
  
  Yes
  - Go To 8
  No
  - Connect the harness connectors to the correct sensors.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
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
  - Repair or replace the leaking exhaust parts as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace the O2 Sensor 1/1 in accordance with the Service Information.
    NOTE:
    Check for signs of contaminants that may have damaged the O2 Sensor, such as contaminated fuel, unapproved silicone, oil and coolant.