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 OTHER DTCS
1. Refer to the recorded DTCs.
  Are there any 5-Volt Reference DTCs active or pending?
  
  Yes
  - Perform the applicable diagnostic procedure(s). Refer to DIAGNOSTIC CODE INDEX .
  No
  - Go To 3
CHECK THE (F853) 5-VOLT SUPPLY CIRCUIT
1. Turn the ignition off.
2. Disconnect the Boost Pressure Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (F853) 5-Volt Supply circuit at the Boost Pressure Sensor harness connector.
  Does the voltage read approximately 5.0 volts?
  
  Yes
  - Go To 4
  No
  - Repair the (F853) 5-Volt Supply circuit for an open or short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST.
CHECK THE (K37) BOOST PRESSURE 1 SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
3. Check for continuity between ground and the (K37) Boost Pressure Signal circuit at the Boost Pressure Sensor harness connector.
  Is there continuity between ground and the (K37) Boost Pressure Signal circuit?
  
  Yes
  - Repair the (K37) Boost Pressure Signal circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST.
  No
  - Go To 5
CHECK THE (K37) BOOST PRESSURE 1 SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K37) Boost Pressure Signal circuit between the Boost Pressure Sensor harness connector and the PCM C2 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 6
  No
  - Repair the (K37) Boost Pressure Signal circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST.
CHECK THE ABILITY OF THE PCM TO READ THE BOOST PRESSURE SENSOR SIGNAL
1. Reconnect the Boost Pressure Sensor harness connector.
2. Reconnect the PCM C2 harness connector.
3. Turn the ignition on.
4. With the scan tool, erase DTCs.
5. Turn the ignition off.
6. Disconnect the Boost Pressure Sensor harness connector.
7. Connect a jumper between the (K37) Boost Pressure Signal circuit and the (F853) 5-Volt Supply circuit.
  NOTE:
  Be careful not to spread the terminals.
8. Turn the ignition on.
9. With the scan tool, read PCM DTCs.
  NOTE:
  The scan tool should display the DTC P0238-TURBOCHARGER/SUPERCHARGER BOOST SENSOR "A" CIRCUIT HIGH with the jumper connected.
  
  Does the scan tool display as described above?
  
  Yes
  - Replace the Boost Pressure Sensor in accordance with the Service Information. Refer to BOOST PRESSURE SENSOR .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 7
CHECK RELATED PCM AND COMPONENT CONNECTIONS
1. Perform any Service Bulletins that apply.
2. Disconnect all PCM harness connectors.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Check for spread terminals and verify proper terminal tension.
  Repair any conditions that are found.
6. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
11. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Replace and program the Powertrain Control Module (PCM) in accordance with the Service information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  - Test complete.