C1400

C1400-TRANSFER CASE RANGE SELECT SWITCH PERFORMANCE





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

- When Monitored:
Drive conditions.

- Set Condition:
The transfer case selector switch is not reporting a valid voltage for any switch position.





1. DTC IS ACTIVE

NOTE: Repair all other DTCs first before proceeding with this test.

1. Ignition on, engine not running.
2. With the scan tool, record and erase DTCs.
3. Test drive the vehicle in each Transfer Case Selector Switch position.
4. With the scan tool, read DTCs.

Is the DTC status Active at this time?

Yes

- Go To 2

No

- Go To 5

2. TRANSFER CASE RANGE SELECT SWITCH VOLTAGE 4WD HIGH
1. Place the Transfer Case Selector Switch in 4WD HI.
2. With the scan tool under Data Display, read the Transfer Case Range Select Switch voltage in the CCN.

Is the voltage approximately 1 volt ( ±.02 of a volt)?

Yes

- Go To 3

No

- Go To 4

3. TRANSFER CASE RANGE SELECT SWITCH VOLTAGE 4WD LO
1. Place the Transfer Case Selector Switch in 4WD LO.
2. With the scan tool under Data Display, read the Transfer Case Range Select Switch voltage in the CCN.

Is the voltage approximately 2.72 volts ( ±.02 of a volt)?

Yes

- Replace the Totally Integrated Power Module (TIPM).
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 4

4. TRANSFER CASE SELECTOR SWITCH




1. Turn the ignition off to the lock position.
2. Disconnect the Transfer Case Selector Switch harness connector.
3. Connect a jumper wire between the (K77) Transfer Case Position Sensor Input circuit and the (K977) Mode Select circuit in the Transfer Case Selector Switch harness connector.
4. Ignition on, engine not running.
5. With the scan tool in Data Display, read the Range Switch voltage in the CCN.

NOTE: The switch voltage should be approximately 5.0 volts ( ±.05 of a volt).

Does the voltage display as described?

Yes

- Replace the Transfer Case Selector Switch.
- Perform the TRANSFER CASE VERIFICATION TEST. Transfer Case Verification Test.

No

- Replace the Totally Integrated Power Module (TIPM).
- Perform the BODY VERIFICATION TEST. Body Verification Test.

5. INTERMITTENT TRANSFER CASE RANGE SELECT SWITCH PERFORMANCE
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.
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.