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Home >> Jeep >> 2009 >> Commander Overland, RWD >> Repair and Diagnosis (Single Page) >> Transmission >> Transfer Case >> (Final Drive Control Module (FDCM) - Electrical Diagnostics) >> DTC Troubleshooting >> C1408-Transfer Case Brake Control Circuit High >> Diagnostic Test
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Diagnostic Test

  1. DTC IS ACTIVE 
    1. Ignition on, engine not running.
    2. With the scan tool, clear DTCs.
    3. Move the Shift control to each position.
    4. With the scan tool, read DTCs.

      Does the DTC reset?

      Yes 

      • Go to step  2

      No 

      • Go to step  5
  2. (T317) TRANSFER CASE MOTOR LOCK SIGNAL CIRCUIT SHORTED TO VOLTAGE 
    Fig 1: Checking Transfer Case Motor Lock Signal Circuit Shorted To Voltage
    GC0120033Courtesy of CHRYSLER LLC
    1. Turn the ignition off to the lock position.
    2. Disconnect the Transfer Case Motor harness connector.
    3. Disconnect the FDCM C1 harness connector.
    4. Ignition on, engine not running.
    5. Measure the voltage of the (T317) Transfer Case Motor Lock Signal circuit.

      Is there any voltage present?

      Yes 

      No 

      • Go to step  3
  3. (T317) TRANSFER CASE MOTOR LOCK SIGNAL CIRCUIT SHORTED TO THE (T301) SWITCHED BATTERY SOLENOID SUPPLY CIRCUIT 
    Fig 2: Checking Transfer Case Motor Lock Signal Circuit Shorted To Switched Battery Solenoid Supply Circuit
    GC0120034Courtesy of CHRYSLER LLC
    1. Turn the ignition off to the lock position
    2. Measure the resistance between the (T317) Transfer Case Motor Lock Signal circuit and the (T301) Switched Battery Solenoid Supply circuit in the Transfer Case Motor harness connector.

      Is the resistance below 5.0 Ohms?

      Yes 

      No 

      • Go to step  4
  4. TRANSFER CASE MOTOR 
    1. Turn the ignition off to the lock position
    2. Connect the FDCM C1 harness connector.
    3. Ignition on, engine not running.
    4. With the scan tool, clear the DTCs.
    5. With the scan tool, read the DTCs.

      Does the DTC P1408-Transfer Case Brake Control Circuit High set?

      Yes 

      No 

  5. 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 

      No 

      • Test complete.