Diagnostic Test

4WD RANGE SWITCH VOLTAGE LESS THAN 0.2 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 less than 0.2 volts?
  
  Yes
  - Go to step 2
  No
  - Go to step 8
TRANSFER CASE SELECTOR SWITCH

Fig 1: Checking Transfer Case Selector Switch
Courtesy of CHRYSLER LLC
1. Turn the ignition off to the lock position
2. Disconnect the Transfer Case Selector Switch harness connector.
3. Connect a jumper wire between the (K504) Drivetrain 5 Volt Supply circuit and the (K977) Mode Select circuit in the Transfer Case Selector Switch harness connector.
4. Ignition on, engine not running.
5. With the scan tool, read the 4WD Range Switch voltage.
6. The switch voltage should be approximately 5.0 volts.
  Does the voltage display as described?
  
  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 VOLTAGE

Fig 2: Checking Drivetrain 5 Volt Supply Circuit Voltage
Courtesy of CHRYSLER LLC
1. Ignition on, engine not running.
2. Measure the voltage of the (K504) Drivetrain 5 Volt Supply circuit.
3. The voltage should be approximately 5.0 volts.
  Does the voltage display as described?
  
  Yes
  - Go to step 6
  No
  - Go to step 4
(K504) DRIVETRAIN 5 VOLT SUPPLY CIRCUIT SHORTED TO GROUND

Fig 3: 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 C2 harness connector.
3. Measure the resistance between ground and the (K504) Drivetrain 5 Volt Supply circuit.
  Is the resistance less than 5.0 ohms?
  
  Yes
  - Repair the (K504) Drivetrain 5 Volt Supply circuit for a short to ground.
  - Perform TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to step 5
(K504) DRIVETRAIN 5 VOLT SUPPLY CIRCUIT OPEN

Fig 4: Checking Drivetrain 5 Volt Supply Circuit Open
Courtesy of CHRYSLER LLC
1. Measure the resistance of the (K504) Drivetrain 5 Volt Supply circuit between the Transfer Case Selector Switch harness connector and the Final Drive Control Module C2 harness connector.
  Is the resistance greater than 5.0 ohms?
  
  Yes
  - Repair the (K504) Drivetrain 5 Volt Supply circuit for an open.
  - 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 .
(K977) MODE SELECT CIRCUIT SHORT TO GROUND

Fig 5: Checking Mode Select Circuit Short To Ground
Courtesy of CHRYSLER LLC
1. Turn the ignition off to the lock position
2. Disconnect the Final Drive Control Module C2 harness connector.
3. Measure the resistance between ground and the (K977) Mode Select circuit.
  Is the resistance less than 5.0 ohms?
  
  Yes
  - Repair the (K977) Mode Select circuit for a short to ground.
  - Perform TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to step 7
(K977) MODE SELECT CIRCUIT OPEN

Fig 6: Checking Mode Select Circuit Open
Courtesy of CHRYSLER LLC
1. Measure the resistance of the (K977) Mode Select circuit between the Transfer Case Selector Switch harness connector and the Final Drive Control Module C2 harness connector.
  Is the resistance above 5.0 ohms?
  
  Yes
  - Repair the (K977) Mode Select circuit for an open.
  - 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.