Diagnostic Test

ACTIVE DTC
1. Ignition on, engine not running.
2. With the scan tool, read DTCs.
  Is the DTC active at this time?
  
  Yes
  - Go to step 2
  No
  - Go to step 6
REAR DIFFERENTIAL SOLENOID OPERATION

Fig 1: Checking Rear Differential Solenoid Operation
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the Rear Differential Solenoid harness connector.
3. Ignition on, engine not running.
4. Using a 12-volt test light, jump across from the (T312) Rear Differential Solenoid Control circuit and the (T301) Switched Battery Solenoid Supply circuit in the Rear Differential Solenoid harness connector.
5. With the scan tool, actuate the Rear Differential Solenoid at 100% duty cycle.
  Does the test light illuminate brightly?
  
  Yes
  - Replace the Rear Differential Solenoid 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
(T312) REAR DIFFERENTIAL SOLENOID CONTROL CIRCUIT SHORTED TO BATTERY VOLTAGE

Fig 2: Checking Rear Differential Solenoid Control Circuit Shorted To Battery Voltage
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the FDCM harness connector.
3. Ignition on, engine not running.
4. Measure the voltage on the (T312) Rear Differential Solenoid Control circuit at the FDCM harness connector.
  Is the voltage above 10 volts?
  
  Yes
  - Repair the short to voltage in the (T312) Rear Differential Solenoid Control circuit.
  - Perform the FDCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to step 4
(T312) REAR DIFFERENTIAL SOLENOID CONTROL CIRCUIT SHORTED TO THE (T301) SWITCHED BATTERY SOLENOID SUPPLY CIRCUIT

Fig 3: Checking Rear Differential Solenoid Control Circuit Shorted To Switched Battery Solenoid Supply Circuit
Courtesy of CHRYSLER LLC
1. Measure the resistance between the (T312) Rear Differential Solenoid Control circuit and the (T301) Switched Battery Solenoid Supply circuit in the FDCM harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Repair the short between the (T312) Rear Differential Solenoid Control circuit and the (T301) Switched Battery Solenoid Supply circuit.
  - Perform the FDCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Go to step 5
FINAL DRIVE CONTROL MODULE (FDCM)
NOTE: Before continuing, check the FDCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
1. Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the FDCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Final Drive Control (FDCM) - Standard Procedure .
  No
  - Replace the Final Drive Control Module (FDCM) in accordance with 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 schematics as a guide, inspect the wiring and connectors specific to this circuit.
3. Wiggle test the wiring harness and connectors while checking for shorted and open circuits.
4. Using the scan tool, monitor the data related to this circuit while performing the wiggle test. Look for the data to change or for the DTC to reset.
  Were there 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 condition or conditions that originally set this DTC are not present at this time.