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 not running.
2. With the scan tool, read DTCs.
  Is the status Active for this DTC?
  
  Yes
  - Go to step 2
  No
  - Go to step 13
(T504) DRIVETRAIN 5 VOLT SUPPLY VOLTAGE ERRATIC

Fig 1: Checking Drivetrain 5 Volt Supply Circuit Voltage
Courtesy of CHRYSLER LLC

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. Turn the ignition off to the lock position
2. Disconnect the Transfer Case Motor harness connector.
3. Ignition on, engine not running.
4. Measure the voltage of the (T504) Drivetrain 5-volt Supply circuit.
  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 step 6
  No
  - Go to step 3
(T504) DRIVETRAIN 5 VOLT SUPPLY CIRCUIT INTERMITTENT SHORT TO VOLTAGE

Fig 2: Checking Drivetrain 5 Volt Supply Circuit Voltage
Courtesy of CHRYSLER LLC
1. Turn the ignition off to the lock position
2. Disconnect the FDCM C2 harness connector.
3. Ignition on, engine not running.
4. Measure the voltage of the (T504) Drivetrain 5-volt Supply circuit.
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 (T504) Drivetrain 5-volt Supply circuit for an intermittent short to voltage.
  - Perform TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to step 4
(T504) DRIVETRAIN 5 VOLT SUPPLY CIRCUIT HIGH RESISTANCE

Fig 3: Checking Drivetrain 5 Volt Supply Circuit High Resistance
Courtesy of CHRYSLER LLC
1. Measure the resistance of the (T504) Drivetrain 5-volt Supply circuit between the Transfer Case Motor harness connector and the Final Drive Control Module C2 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 (T504) Drivetrain 5-volt Supply circuit for an intermittent open circuit or high resistance.
  - Perform TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to step 5
(T504) DRIVETRAIN 5 VOLT SUPPLY CIRCUIT INTERMITTENT SHORT TO GROUND

Fig 4: Checking Drivetrain 5 Volt Supply Circuit Shorted To Ground
Courtesy of CHRYSLER LLC
1. Measure the resistance between ground and the (T504) Drivetrain 5-volt Supply circuit.
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 (T504) Drivetrain 5-volt Supply circuit for an intermittent short to ground.
  - Perform 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 TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
T-CASE POSITION SENSOR VOLTAGE

Fig 5: Checking Transfer Case Motor
Courtesy of CHRYSLER LLC
1. Turn the ignition off to the lock position
2. Reconnect the FDCM C2 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 Motor harness connector.
4. Ignition on, engine not running.
5. With the scan tool read the T-Case Position Sensor Voltage in the FDCM while performing a wiggle test on the wiring and connectors between the sensor and the control module.
  NOTE: Voltage should be approximately 0.0 volts and steady.
  
  Is the T-Case Position Sensor Voltage approximately 0.0 volts and steady?
  
  Yes
  - Go to step 12
  No
  - Go to step 7
(T313) MODE SENSOR SIGNAL CIRCUIT INTERMITTENT SHORT TO VOLTAGE

Fig 6: Checking Mode Sensor Signal Circuit Shorted 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 C2 harness connector.
3. Ignition on, engine not running.
4. Measure the voltage of the (T313) Mode Sensor Signal circuit.
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 an intermittent short to voltage.
  - Perform TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to step 8
(K594) DRIVETRAIN SENSOR RETURN CIRCUIT INTERMITTENT SHORT TO VOLTAGE

Fig 7: Checking Drivetrain Sensor Return Circuit Intermittent Short To Voltage
Courtesy of CHRYSLER LLC
1. Measure the voltage of the (K594) Drivetrain Sensor Return circuit.
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 an intermittent short to voltage.
  - Perform TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to step 9
(T313) MODE SENSOR SIGNAL CIRCUIT HIGH RESISTANCE

Fig 8: Checking Mode Sensor Signal Circuit 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 Motor 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 TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to step 10
(K594) DRIVETRAIN SENSOR RETURN CIRCUIT HIGH RESISTANCE

Fig 9: Checking Drivetrain Sensor Return Circuit High Resistance
Courtesy of CHRYSLER LLC
1. Measure the resistance of the (K594) Drivetrain Sensor Return circuit between the Transfer Case Motor harness connector and the FDCM C2 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 TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to step 11
(T313) MODE SENSOR SIGNAL CIRCUIT INTERMITTENT SHORT TO GROUND

Fig 10: Checking Mode Sensor Signal Circuit Shorted To Ground
Courtesy of CHRYSLER LLC
1. Measure the resistance between ground and the (T313) Mode Sensor Signal circuit.
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 (T313) Mode Sensor Signal circuit for an intermittent short to ground.
  - Perform 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 TRANSFER CASE VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
TRANSFER CASE MOTOR
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. Using the schematic as a guide, inspect the Final Drive Control Module power and ground circuits.
  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
  - Replace the Transfer Case Motor 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.
  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.