C140A

C140A-TRANSFER CASE MOTOR PERFORMANCE





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

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

- Set Condition:
A faulted condition is detected in the H-bridge driver.





1. DTC ACTIVE
1. Ignition on, engine not running.
2. With the scan tool, record and erase DTCs.
3. Test drive the vehicle.
4. Ignition on, engine not running.
5. With the scan tool, read DTCs.

Is DTC active?

Yes

- Go To 2

No

- Go To 5

2. (T315) STEP MOTOR CONTROL B CIRCUIT SHORTED TO GROUND




1. Turn the ignition off to the lock position.
2. Disconnect the Transfer Case Motor harness connector.
3. Ignition on, engine not running.
4. Measure the resistance between ground and the (T315) Step Motor Control B circuit at the Transfer Case Motor harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Repair the (T315) Step Motor Control B circuit for a short to ground.
- Perform the TRANSFER CASE VERIFICATION TEST Transfer Case Verification Test

No

- Go To 3

3. (T316) STEP MOTOR CONTROL C CIRCUIT SHORTED TO GROUND




1. Measure the resistance between ground and the (T316) Step Motor Control C circuit at the Transfer Case Motor harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Repair the (T316) Step Motor Control C circuit for a short to ground.
- Perform the TRANSFER CASE VERIFICATION TEST. Transfer Case Verification Test.

No

- Go To 4

4. (T315) STEP MOTOR CONTROL B CIRCUIT SHORTED TO THE (T316) SHIFT MOTOR CONTROL B CIRCUIT




1. Measure the resistance between the (T315) Step Motor Control B circuit and the (T316) Step Motor Control C circuit at the Transfer Case Motor harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Repair the short between the (T315) Step Motor Control B circuit and the (T316) Step Motor Control C circuit.
- Perform the TRANSFER CASE VERIFICATION TEST. Transfer Case Verification Test.

No

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

5. INTERMITTENT WIRING HARNESS 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. Wiggle test the wiring harness and connectors while monitoring the scan tool data relative to this circuit.
4. Look for the data to change or for the DTC to reset during the wiggle test.
5. While monitoring the scan tool data relative to this circuit, move the selector switch to each position several times.
6. Look for the data to change other than as expected or for the DTC to reset.

Were any problems found?

Yes

- Repair as necessary.
- Perform the TRANSFER CASE VERIFICATION TEST. Transfer Case Verification Test.

No

- Test complete.