Diagnostic Test

4WD RANGE SWITCH VOLTAGE ABOVE 4.5 VOLTS
1. Ignition on, engine not running.
  NOTE: Repair any system undervoltage or overvoltage DTCs that are set in this module before proceeding.
2. With the scan tool, read the 4WD Range Switch voltage in the Final Drive Control Module.
  Is the voltage above 4.5 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, read the 4WD Range Switch voltage in the FDCM.
  Is the voltage equal to 0 volts?
  
  Yes
  - Replace the Transfer Case Selector Switch.
  - Perform TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to step 3
(K504) DRIVETRAIN 5 VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE

Fig 1: Checking Drivetrain 5 Volt Supply Circuit Shorted To Voltage
Courtesy of CHRYSLER LLC
1. Measure the voltage of the (K504) Drivetrain 5 Volt Supply circuit.
  Is the voltage above 5.5 volts?
  
  Yes
  - Repair the (K504) Drivetrain 5 Volt Supply circuit for a short to voltage.
  - Perform TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to step 4
(K977) MODE SELECT CIRCUIT SHORTED TO VOLTAGE

Fig 2: Checking Mode Select Circuit Shorted To Voltage
Courtesy of CHRYSLER LLC
1. Turn the ignition off to the lock position
2. Disconnect the Final Drive Control Module C2 harness connector.
3. Ignition on, engine not running.
4. Measure the voltage of the K977) Mode Select circuit.
  Is there any voltage present?
  
  Yes
  - Repair the (K977) Mode Select circuit for a short to voltage.
  - Perform TRANSFER CASE 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 TRANSFER CASE 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.
5. While monitoring the scan tool data relative to this circuit, move the selector switch to each position several times.
6. Look for the data to change other than as expected or for the DTC to reset.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Test complete.