Diagnostic Test

DTC IS ACTIVE
NOTE: This DTC sets when the Final Drive Control Module (FDCM) detects excessive voltage fluctuation on the Mode Sensor Signal circuit. Perform a thorough inspection of all wiring and connectors between the sensor and the control module.
1. Ignition on, engine off.
2. With the scan tool, read DTCs.
  Is the status Active for this DTC?
  
  Yes
  - Go to 2
  No
  - Go to 14
(K504) DRIVETRAIN 5-VOLT SUPPLY VOLTAGE ERRATIC

Fig 1: Checking Drivetrain Five Volt Supply Circuit For Erratic Voltage Fluctuation
Courtesy of CHRYSLER LLC

NOTE: This DTC sets when the FDCM detects excessive voltage fluctuation on the Mode Sensor Signal circuit. Perform a thorough inspection of all wiring and connectors between the sensor and the control module.
1. Turn the ignition off to the lock position
2. Disconnect the Transfer Case Encoder harness connector.
3. Ignition on, engine off.
4. Measure the voltage of the (K504) Drivetrain 5-volt Supply circuit at the Transfer Case Encoder harness connector.
  NOTE: Voltage should be approximately 5.0 volts and steady. Compare any slight fluctuations found to a known good circuit in order to verify voltmeter functionality.
  
  Is the voltage approximately 5.0 volts and steady?
  
  Yes
  - Go to 6
  No
  - Go to 3
(K504) DRIVETRAIN 5-VOLT SUPPLY CIRCUIT INTERMITTENT SHORT TO VOLTAGE

Fig 2: Checking Drivetrain Five Volt Supply Circuit For Short To Voltage
Courtesy of CHRYSLER LLC
1. Turn the ignition off to the lock position
2. Disconnect the FDCM C1 harness connector.
3. Ignition on, engine off.
4. Measure the voltage of the (K504) Drivetrain 5-volt Supply circuit at the Transfer Case Encoder harness connector.
5. Monitor the voltmeter while performing a wiggle test on the wiring harness and connectors.
  Is any voltage detected on the circuit during the wiggle test?
  
  Yes
  - Repair the (K504) Drivetrain 5-volt Supply circuit for an intermittent short to voltage.
  - Perform the TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to 4
(K504) DRIVETRAIN 5-VOLT SUPPLY CIRCUIT HIGH RESISTANCE

Fig 3: Checking Drivetrain Five Volt Supply Circuit For Open Circuit Or High Resistance
Courtesy of CHRYSLER LLC
1. Measure the resistance of the (K504) Drivetrain 5-volt Supply circuit between the Transfer Case Encoder harness connector and the FDCM C1 harness connector.
2. Monitor the ohmmeter while performing a wiggle test on the wiring harness and connectors.
  Is the resistance ever above 5.0 Ohms during the wiggle test?
  
  Yes
  - Repair the (K504) Drivetrain 5-volt Supply circuit for an intermittent open circuit or high resistance.
  - Perform the TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to 5
(K504) DRIVETRAIN 5-VOLT SUPPLY CIRCUIT SHORT TO GROUND

Fig 4: Checking Drivetrain Five Volt Supply Circuit For Short To Ground
Courtesy of CHRYSLER LLC
1. Measure the resistance between ground and the (K504) Drivetrain 5-volt Supply circuit at the Transfer Case Encoder harness connector.
2. Monitor the ohmmeter while performing a wiggle test on the wiring harness and connectors.
  Is the resistance ever below 5.0 Ohms during the wiggle test?
  
  Yes
  - Repair the short to ground in the (K504) Drivetrain 5-volt Supply circuit.
  - Perform the TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Replace the Final Drive Control Module (FDCM) in accordance with the Service Information.
  - Perform the TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
TRANSFER CASE POSITION SENSOR VOLTAGE

Fig 5: Checking Transfer Case Position Sensor Voltage
Courtesy of CHRYSLER LLC
1. Turn the ignition off to the lock position
2. Reconnect the FDCM C1 harness connector.
3. Connect a jumper wire between the (T313) Mode Sensor Signal circuit and the (K594) Drivetrain Sensor Return circuit in the Transfer Case Encoder harness connector.
4. Ignition on, engine off.
5. With the scan tool read the Transfer Case Position Sensor Voltage in the FDCM while performing a wiggle test on the wiring and connectors between the sensor and the control module.
  Is the T-Case Position Sensor Voltage approximately zero volts and steady?
  
  Yes
  - Go to 12
  No
  - Go to 7
(T313) MODE SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE

Fig 6: Checking Mode Sensor Signal Circuit For Short To Voltage
Courtesy of CHRYSLER LLC

NOTE: Remove the previously installed jumper wire.
1. Turn the ignition off to the lock position
2. Disconnect the FDCM C1 harness connector.
3. Ignition on, engine off.
4. Measure the voltage of the (T313) Mode Sensor Signal circuit at the Transfer Case Encoder harness connector.
5. Monitor the voltmeter while performing a wiggle test on the wiring harness and connectors.
  Is any voltage detected on the circuit during the wiggle test?
  
  Yes
  - Repair the (T313) Mode Sensor Signal circuit for a short to voltage.
  - Perform the TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to 8
(K594) DRIVETRAIN SENSOR RETURN CIRCUIT SHORTED TO VOLTAGE

Fig 7: Checking Drivetrain Sensor Return Circuit For Short To Voltage
Courtesy of CHRYSLER LLC
1. Measure the voltage of the (K594) Drivetrain Sensor Return circuit at the Transfer Case Encoder harness connector.
2. Monitor the voltmeter while performing a wiggle test on the wiring harness and connectors.
  Is any voltage detected on the circuit during the wiggle test?
  
  Yes
  - Repair the (K594) Drivetrain Sensor Return circuit for a short to voltage.
  - Perform the TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to 9
(T313) MODE SENSOR SIGNAL CIRCUIT HIGH RESISTANCE

Fig 8: Checking Mode Sensor Circuit For Open Circuit Or High Resistance
Courtesy of CHRYSLER LLC
1. Turn the ignition off to the lock position.
2. Measure the resistance of the (T313) Mode Sensor Signal circuit between the Transfer Case Encoder harness connector and the FDCM C2 harness connector.
3. Monitor the ohmmeter while performing a wiggle test on the wiring harness and connectors.
  Is the resistance ever above 5.0 Ohms during the wiggle test?
  
  Yes
  - Repair the (T313) Mode Sensor Signal circuit for an intermittent open circuit or high resistance.
  - Perform the TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to 10
(K594) DRIVETRAIN SENSOR RETURN CIRCUIT HIGH RESISTANCE

Fig 9: Checking Drivetrain Sensor Return Circuit For Open Circuit Or High Resistance
Courtesy of CHRYSLER LLC
1. Measure the resistance of the (K594) Drivetrain Sensor Return circuit between the Transfer Case Encoder harness connector and the FDCM C1 harness connector.
2. Monitor the ohmmeter while performing a wiggle test on the wiring harness and connectors.
  Is the resistance ever above 5.0 Ohms during the wiggle test?
  
  Yes
  - Repair the (K594) Drivetrain Sensor Return circuit for an intermittent open circuit or high resistance.
  - Perform the TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to 11
(T313) MODE SENSOR SIGNAL CIRCUIT INTERMITTENT SHORTED TO GROUND

Fig 10: Checking Mode Sensor Signal Circuit For Short To Ground
Courtesy of CHRYSLER LLC
1. Measure the resistance between ground and the (T313) Mode Sensor Signal circuit at the Transfer Case Encoder harness connector.
2. Monitor the ohmmeter while performing a wiggle test on the wiring harness and connectors.
  Is the resistance ever below 5.0 Ohms during the wiggle test?
  
  Yes
  - Repair the short to ground in the (T313) Mode Sensor Signal circuit.
  - Perform the TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to 12
INSPECT FINAL DRIVE CONTROL MODULE (FDCM) POWER AND GROUNDS
NOTE: This DTC sets when the FDCM detects excessive voltage fluctuation on the Mode Sensor Signal circuit. Perform a thorough inspection of all wiring and connectors between the sensor and the control module.
1. Using the schematic as a guide, inspect the Final Drive Control Module (FDCM) power and ground circuits.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  
  Go to 13
TRANSFER CASE ENCODER
1. Replace the Transfer Case Encoder in accordance with the Service Information.
  Perform the TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
2. Test drive the vehicle.
3. With the scan tool, read the DTCs.
  Does this DTC reset?
  
  Yes
  - Replace the Final Drive Control Module (FDCM) in accordance with the Service Information.
  - Perform the TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  
  Test complete.
INTERMITTENT WIRING HARNESS AND CONNECTORS
1. The conditions necessary to set this DTC are not present at this time.
2. Using the wiring diagram/schematic as a guide, inspect the wiring harness and connectors.
3. Wiggle test the wiring harness and connectors while monitoring the scan tool data relative to this circuit.
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 TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Test complete.