Diagnostic Test

WARNING: This page is about a different car, the 2025 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR AN ACTIVE DTC
WARNING:
On vehicles equipped with the high voltage system, you must thoroughly read and follow all High Voltage Safety procedures. In addition, before performing any diagnostic or service procedure near a high voltage component, you must perform the High Voltage Power Down. Failure to follow these instructions may result in possible serious or fatal injury.

Read the HIGH-VOLTAGE SAFETY PROCEDURES. Refer to HIGH VOLTAGE SAFETY PROCEDURES .

When the HIGH-VOLTAGE POWER-DOWN PROCEDURE is necessary. Refer to HIGH VOLTAGE POWER DOWN .
1. With the scan tool, read DTCs and record on the repair order.
2. Record the Environmental Data.
3. With the scan tool, erase DTCs.
  NOTE:
  This DTC cannot be erased unless the vehicle is operated over 8 mph (12.8 kph) for a short period of time.
4. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
5. With the scan tool, read Integrated Dual Charge Module (IDCM) DTCs.
  Did the DTC return?
  
  Yes
  - Go To Next Step.
  No
  - Perform the TESTING FOR AN INTERMITTENT CONDITION diagnostic procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK ELECTRIC VEHICLE SUPPLY EQUIPMENT (EVSE) CHARGING CAPABILITY
1. Connect the customers EVSE Charging Unit to the vehicle. Using the Scan Tool, Monitor the AC output and the Proximity Signal Value.
2. If the customer's EVSE is not available, use a known good EVSE to perform this test.
  Is the EVSE Charging Unit operating correctly?
  
  Yes
  - Advise the customer that the problem may be with their power source connection for the EVSE Charging Unit.
  - Perform the INTEGRATED DUAL CHARGE MODULE (IDCM) VERIFICATION TEST. Refer to INTEGRATED DUAL CHARGE MODULE (IDCM) VERIFICATION TEST .
  No
  - Go To Next Step.
CHECK THE (H328) CHARGING PORT PROXIMITY DETECTION SIGNAL CIRCUIT FOR AN OPEN
1. Turn the ignition on.
2. Using a multimeter, check the voltage of the (H328) Charging Port Proximity Detection Signal circuit at the Charge Port.
  Is the measured voltage 4.9 volts or higher?
  
  Yes
  - Go To Next Step.
  No
  - Replace the Charge Port harness in accordance with the Service Information.
  - Perform the INTEGRATED DUAL CHARGE MODULE (IDCM) VERIFICATION TEST. Refer to INTEGRATED DUAL CHARGE MODULE (IDCM) VERIFICATION TEST .
CHECK THE IDCM FOR AN INTERNAL FAILURE
1. Turn the Ignition on.
2. Using a multimeter, back-probe and check the voltage on the (H328) Charging Port Proximity Detection Signal circuit at the IDCM C4 connector (IDCM side).
  Is the measured voltage 4.9 volts or higher?
  
  Yes
  - Perform the TESTING FOR AN INTERMITTENT CONDITION diagnostic procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
  No
  - Go To Next Step.
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all IDCM 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.
  - Perform a terminal drag test on each connector terminal to verify proper terminal tension.
  Repair any conditions that are found.
5. Reconnect all IDCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Reconnect 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. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
10. With the scan tool, read IDCM DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Integrated Dual Charge Module (IDCM) in accordance with the Service Information. Refer to MODULES, HIGH VOLTAGE SYSTEM, REMOVAL AND INSTALLATION .
  - Perform the INTEGRATED DUAL CHARGE MODULE (IDCM) VERIFICATION TEST. Refer to INTEGRATED DUAL CHARGE MODULE (IDCM) VERIFICATION TEST .
  No
  - The wiring or poor connection problem has been repaired.
  - Perform the INTEGRATED DUAL CHARGE MODULE (IDCM) VERIFICATION TEST. Refer to INTEGRATED DUAL CHARGE MODULE (IDCM) VERIFICATION TEST .