C1408

C1408-TRANSFER CASE BRAKE CONTROL CIRCUIT HIGH





For a complete wiring diagram, refer to the Wiring Information.

- When Monitored:
With the ignition on and no undervoltage or overvoltage condition present.

- Set Condition:
The Final Drive Control Module detects that the Transfer Case Motor Lock Circuit diagnostic input is high when the output is on.





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 2

No

- Go To 5

2. (T317) TRANSFER CASE MOTOR LOCK SIGNAL CIRCUIT SHORTED TO VOLTAGE




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

- Repair the (T317) Transfer Case Motor Lock Signal circuit for a short to voltage.
- Perform the TRANSFER CASE VERIFICATION TEST. .

No

- Go To 3

3. (T317) TRANSFER CASE MOTOR LOCK SIGNAL CIRCUIT SHORTED TO THE (T301) SWITCHED BATTERY SOLENOID SUPPLY CIRCUIT




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

- Repair the (T317) Transfer Case Motor Lock Signal circuit for a short to the (T301) Switched Battery Solenoid Supply circuit.
- Perform the TRANSFER CASE VERIFICATION TEST. .

No

- Go To 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

- Replace the Transfer Case Motor assembly.
- Perform the TRANSFER CASE VERIFICATION TEST. .

No

- Replace the Final Drive Control Module (FDCM).
- Perform the TRANSFER CASE VERIFICATION TEST. .

5. INTERMITTENT WIRING 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 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 the TRANSFER CASE VERIFICATION TEST. .

No

- Test complete.