Front Control Module (FCM)

C1404-TRANSFER CASE RANGE POSITION SENSOR CIRCUIT LOW





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

- When Monitored:
Ignition on. Battery voltage between 9.0 and 16.0 volts.

- Set Condition:
Front Control Module (FCM) detects a short to ground on the Transfer Case Position Sensor signal circuit for Two seconds.





1. TRANSFER CASE POSITION SENSOR VOLTAGE BELOW 0.2 VOLTS
1. Ignition on, engine not running.
2. With the scan tool, read the Transfer Case Position Sensor voltage.

Is the voltage below 0.2 volts?

Yes

- Go To 2

No

- Go To 7

2. (T103) 5-VOLT SUPPLY CIRCUIT VOLTAGE BELOW 0.2 VOLTS




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 between ground and the (T103) 5-volt Supply circuit.

Is the voltage below 0.2 volts?

Yes

- Go To 3

No

- Go To 5

3. (T103) 5-VOLT SUPPLY CIRCUIT OPEN




1. Turn the ignition off to the lock position.
2. Disconnect the Front Control Module C1 harness connector.
3. Measure the resistance of the (T103) 5-volt Supply circuit between the Shift Motor/Mode Sensor harness connector and the Front Control Module C1 harness connector.

Is the resistance above 5.0 ohms?

Yes

- Repair the (T103) 5-volt Supply circuit for an open.
- Perform the TRANSFER CASE VERIFICATION TEST Transfer Case Verification Test

No

- Go To 4

4. (T103) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND




1. Measure the resistance between ground and the (T103) 5-volt Supply circuit.

Is the resistance below 5.0 ohms?

Yes

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

No

- Go To 5

5. TRANSFER CASE POSITION SENSOR VOLTAGE
1. With the scan tool, read the Transfer Case Position Sensor voltage.

Is the voltage above 4.5 volts?

Yes

- Go To 6

No

- Replace the Front Control Module.
- Perform the TRANSFER CASE VERIFICATION TEST Transfer Case Verification Test
6. (D201) MODE SENSOR A CIRCUIT SHORTED TO GROUND




1. Turn the ignition off to the lock position.
2. Measure the resistance between ground and the (D201) Mode Sensor A circuit.

Is the resistance below 5.0 ohms?

Yes

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

No

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

7. CHECK THE 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 Transfer Case Verification Test

No

- Test complete.