Diagnostic Test

VERIFY THE DIAGNOSTIC TROUBLE CODE (DTC) IS ACTIVE
NOTE: Ensure the IOD fuse is installed and battery voltage is between 10 and 16 volts before proceeding.
1. With the scan tool, read active DTCs.
  Is this DTC active?
  
  Yes
  - Go to step 2
  No
  - Refer to the Stored Lost Communication test procedure. Refer to Non-DTC Diagnostics/Communication - Diagnosis and Testing
CHECK FOR ANY OF THE FOLLOWING ACTIVE DTC'S
1. With the scan tool, read active DTCs from all modules.
  NOTE: Check for FCM configuration, CAN B or C hardware electrical, VIN Missing/Mismatch, battery or ignition related DTCs.
  
  Does the scan tool display any active DTCs to the conditions listed above?
  
  Yes
  - Go to and perform the appropriate diagnostic procedure.
  No
  - Go to step 3
VERIFY THAT THE TM IS ACTIVE ON THE BUS
1. Turn the ignition on.
2. With the scan tool, select Network View and select Advanced.
  NOTE: A red X will be next to the module that is not communicating, indicating that the module is not active on the Bus network. A green check indicates that the module is active on the Bus network.
3. Verify that the TM is active on the bus.
  Is the TM active on the bus?
  
  Yes
  - Replace and program the Front Control Module in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure
  No
  - Go to step 4
(A922) (A907) FUSED B(+) CIRCUITS OPEN

Fig 1: Checking Fused B(+) Circuits Open
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the Trailer Lighting Module C2 harness connector.
3. Using a 12-volt test light connected to ground, check the (A922) and (A907) Fused B(+) circuits.
  Does the test light illuminate brightly on each circuit?
  
  Yes
  - Go to step 5
  No
  - Repair the (A922) or (A907) Fused B(+) circuit for an open or short.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure
(F941) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT OPEN

Fig 2: Checking Fused Ignition Switch Output (Run-Start) Circuit Open
Courtesy of CHRYSLER LLC
1. Turn the ignition on.
2. Disconnect the Trailer Lighting Module C4 harness connector.
3. Using a 12-volt test light connected to ground, check the (F941) Fused Ignition Switch Output circuit.
  Does the test light illuminate brightly?
  
  Yes
  - Go to step 6
  No
  - Repair the (F941) Fused Ignition Switch Output circuit for an open or short.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure
(Z923) GROUND CIRCUIT OPEN

Fig 3: Checking Ground Circuit Open
Courtesy of CHRYSLER LLC
1. Using a 12-volt test light connected to 12-volts, check the (Z923) ground circuit.
  Does the test light illuminate brightly?
  
  Yes
  - Go to step 7
  No
  - Repair the (Z923) ground circuit for an open.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure
(D55) AND (D54) CAN B BUS CIRCUITS OPEN

Fig 4: Checking CAN B BUS Circuits Open
Courtesy of CHRYSLER LLC

NOTE: One open circuit will not cause this condition.
1. Measure the voltage between the (D54) CAN B Bus (-) circuit and ground.
2. Measure the voltage between the (D55) CAN B Bus (+) circuit and ground.
  Is there any voltage present on either circuit?
  
  Yes
  - Replace the Trailer Lighting Module in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure
  No
  - Repair the (D55) and (D54) CAN B Bus circuits for an open. Inspect the connector for damage.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure