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.

CHECK FOR AN ACTIVE DIAGNOSTIC TROUBLE CODE (DTC)
1. Turn the ignition on.
2. With the scan tool, view DTCs.
  Is the DTC active?
  
  Yes
  - Go To Next Step
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
INSPECT THE ACTIVE GRILL SHUTTER ASSEMBLY FOR SIGNS OF PHYSICAL DAMAGE
1. Inspect the Active Grill Shutter Assembly and connector for damage due to road debris.
  Is the Active Grill Shutter Assembly or connector damaged or disconnected?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To Next Step
CHECK THE COMPONENTS THAT SHARE THE LIN
1. IMPORTANT - FOLLOW THIS PROCEDURE EXACTLY WHEN CHECKING THE FOLLOWING COMPONENTS: Turn the ignition off before disconnecting each component. After a component has been disconnected, turn the ignition on and test the function of the AGS. If the fault does not return after disconnecting a component, the component that was disconnected is faulty. If the fault remains after disconnecting a component, then the disconnected component is not the problem. Leave each component disconnected and move on to the next until the faulty component is discovered or all components have been disconnected. Disconnect only one component at a time during this step.
2. Disconnect the upper Active Air Dam (If equipped).
3. Disconnect the lower AGS (If equipped).
4. Disconnect the Three way coolant valve (If equipped).
5. Disconnect the Auxiliary Coolant Pump (If equipped).
  Were any of the above components determined to be at fault?
  
  Yes
  - Replace the faulty component in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To Next Step
CHECK THE (A433) FUSED B+ CIRCUIT FOR PROPER VOLTAGE
1. Turn the ignition off.
2. Disconnect the AGS harness connector.
3. Measure the voltage at the (A433) Fused B+ circuit at the AGS harness connector.
  NOTE:
  The (A433) Fused B+ circuit is supplied to two terminals at the AGS Assembly. Be sure to check both circuits.
  
  Is the voltage equal to battery voltage?
  
  Yes
  - Go To Next Step
  No
  - Repair the (A433) Fused B+ circuit for an open or short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (Z923) GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance between ground and the (Z923) Ground circuit at the AGS harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To Next Step
  No
  - Repair the (Z923) Ground circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (D511) LIN BUS CIRCUIT FOR A SHORT TO GROUND
1. Disconnect the PCM C1 harness connector.
2. Measure the resistance between ground and the (D511) LIN BUS circuit at the AGS harness connector.
  Is the resistance above 10k Ohms?
  
  Yes
  - Go To Next Step
  No
  - Repair the (D511) LIN BUS circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (D511) LIN BUS CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (D511) LIN BUS circuit between the AGS harness connector and the PCM C1 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To Next Step
  No
  - Repair the (D511) LIN BUS circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE ACTIVE GRILL SHUTTER ASSEMBLY FOR PROPER OPERATION
1. Replace the Active Grill Shutter Assembly in accordance with the service information. Navigate to Miscellaneous functions and perform the 'Active Grille Shutter Replaced' procedure.
2. Reconnect the PCM C1 harness connector.
3. Turn the ignition on.
4. With the scan tool, erase DTCs.
5. With the scan tool, actuate the AGS Assembly.
6. With the scan tool, view DTCs.
  Did the DTC return?
  
  Yes
  - Go To Next Step
  No
  - Repair complete.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all PCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. 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.
5. Connect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
10. 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.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Repair the poor connections.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .