Diagnostic Test

DRIVETRAIN 5-VOLT SUPPLY (REFERENCE) VOLTAGE BELOW 4.8 VOLTS
1. Ignition on, engine not running.
2. With the scan tool, read the Drivetrain 5-volt Supply (Reference) Voltage in the FDCM.
  Is the voltage below 4.8 volts?
  
  Yes
  - Go to step 2
  No
  - Go to step 5
TRANSFER CASE SELECTOR SWITCH
1. Turn the ignition off to the lock position
2. Disconnect the Transfer Case Selector Switch harness connector.
3. Ignition on, engine not running.
4. With the scan tool, monitor the 5-volt Supply (Reference) Voltage.
  Is the voltage above 4.75 volts with the Transfer Case Selector Switch harness disconnected?
  
  Yes
  - Replace the Transfer Case Selector Switch in accordance with the Service Information.
  - Perform the FDCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to step 3
TRANSFER CASE MOTOR
1. Turn the ignition off to the lock position
2. Disconnect the Transfer Case Motor harness connector.
3. Ignition on, engine not running.
4. With the scan tool, read the 5-volt Supply (Reference) Voltage.
  Is the voltage above 4.75 volts with the Transfer Case Motor harness disconnected?
  
  Yes
  - Replace the Transfer Case Motor in accordance with the Service Information.
  - Perform the FDCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to step 4
(K504) DRIVETRAIN 5 VOLT SUPPLY CIRCUIT SHORT TO GROUND

Fig 1: Checking Drivetrain 5 Volt Supply Circuit Shorted To Ground
Courtesy of CHRYSLER LLC
1. Turn the ignition off to the lock position
2. Disconnect the Final Drive Control Module harness connector.
3. Measure the resistance between ground and the (K504) Drivetrain 5- volt Supply circuit.
  Is the resistance below 5.0 ohms?
  
  Yes
  - Repair the (K504) Drivetrain 5 Volt Supply circuit for a short to ground.
  - Perform the FDCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Replace the Final Drive Control Module in accordance with the Service information.
  - Perform the FDCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
INTERMITTENT WIRING AND CONNECTORS
1. The conditions necessary to set this DTC are not present at this time.
2. Using the SYSTEM WIRING DIAGRAMS as a guide, inspect the wiring and connectors.
3. While monitoring the scan tool data relative to this circuit, wiggle test the wiring and connectors.
4. Look for the data to change or for the DTC to reset during the wiggle test.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the FDCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Test complete. The conditions that originally set this DTC are not present at this time.