Front Control Module (FCM)

C1405- TRANSFER CASE RANGE POSITION SENSOR CIRCUIT HIGH





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

- When Monitored:
With the ignition on. Battery voltage between 9.0 and 16.0 volts

- Set Condition:
The Front Control Module (FCM) detects 5.0 volts on the Transfer Case Range Position Sensor signal circuit for two seconds.





1. TRANSFER CASE POSITION SENSOR VOLTAGE ABOVE 4.8 VOLTS
1. Ignition on, engine not running.
2. With the scan tool, read the Transfer Case Position Sensor voltage.

Is the voltage above 4.8 volts?

Yes

- Go To 2

No

- Go To 8

2. (T103) 5 VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE




1. Turn the ignition off to the lock position.
2. Disconnect the Shift Motor/Mode Sensor harness connector.
3. Ignition on, engine not running.
4. Measure the voltage of the (T103) 5 Volt Supply circuit.

Is the voltage above 5.5 volts?

Yes

- Repair the (T103) 5 Volt Supply circuit for a short to voltage.
- Perform the TRANSFER CASE VERIFICATION TEST Transfer Case Verification Test

No

- Go To 3

3. (D201) MODE SENSOR A CIRCUIT SHORTED TO VOLTAGE




1. Measure the voltage of the (D201) Mode Sensor A circuit.

Is the voltage above 5.5 volts?

Yes

- Repair the (D201) Mode Sensor A circuit for a short to voltage.
- Perform the TRANSFER CASE VERIFICATION TEST Transfer Case Verification Test

No

- Go To 4

4. SHIFT MOTOR/MODE SENSOR ASSEMBLY




1. Turn the ignition off to the lock position.
2. Connect a jumper wire between the (G180) FCM Sensor Return circuit and the (D201) Mode Sensor A circuit in the Shift Motor/Mode Sensor harness connector.
3. Ignition on, engine not running.
4. With the scan tool, read the Transfer Case Position Sensor voltage.

NOTE: Remove the jumper wire before continuing.

Is the voltage below 0.2 volts?

Yes

- Replace the Shift Motor/Mode Sensor assembly.
- Perform the TRANSFER CASE VERIFICATION TEST . Transfer Case Verification Test

No

- Go To 5

5. (D201) MODE SENSOR A CIRCUIT OPEN




1. Turn the ignition off to the lock position.
2. Disconnect the FCM C1 harness connector.
3. Measure the resistance of the (D201) Mode Sensor A circuit between the Shift Motor/Mode Sensor harness connector and the FCM C1 harness connector.

Is the resistance above 5.0 Ohms?

Yes

- Repair the open in the (D201) Mode Sensor A circuit.
- Perform the TRANSFER CASE VERIFICATION TEST Transfer Case Verification Test

No

- Go To 6

6. (G180) FCM SENSOR RETURN CIRCUIT OPEN




1. Disconnect the FCM IPM harness connector.
2. Measure the resistance of the (G180) FCM Sensor Return circuit between the Shift Motor/Mode Sensor harness connector and the FCM IPM harness connector.

Yes

- Repair the open in the (G180) FCM Sensor Return circuit.
- Perform the TRANSFER CASE VERIFICATION TEST Transfer Case Verification Test

No

- Go To 7

7. FRONT CONTROL MODULE (FCM)

View repair.

Repair

- Replace the Front Control Module (FCM).
- Perform the TRANSFER CASE VERIFICATION TEST Transfer Case Verification Test

8. 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 harness and connectors.
3. While monitoring the scan tool data relative to this circuit, wiggle test the wiring harness 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 Transfer Case Verification Test

No

- Test complete.