P0839

P0839-FOUR WHEEL DRIVE (4WD) SWITCH CIRCUIT HIGH





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

- When Monitored:
Ignition on.

- Set Condition:
The Transfer Case Position Sensor Input circuit voltage is above a specified value for a calibrated amount of time.





1. CHECK FOR AN ACTIVE DIAGNOSTIC TROUBLE CODE (DTC)
1. Turn the ignition on.
2. Using the scan tool, read DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 2

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.

2. (K77) TRANSFER CASE POSITION SENSOR INPUT CIRCUIT SHORTED TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the Transfer Case Selector Switch harness connector.
3. Turn the ignition on.
4. Measure the voltage of the (K77) Transfer Case Position Sensor Input circuit at the Transfer Case Selector Switch harness connector.

Is the voltage above 5.0 volts?

Yes

- Repair the (K77) Transfer Case Position Sensor Input circuit for a short to voltage.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 3

3. TRANSFER CASE SELECTOR SWITCH
1. Turn the ignition off.
2. 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.
3. Turn the ignition on.
4. Using the scan tool, read the DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 4

No

- Replace the Transfer Case Selector Switch. .
- Perform the BODY VERIFICATION TEST. Body Verification Test.

4. (K77) TRANSFER CASE POSITION SENSOR INPUT CIRCUIT OPEN
1. Turn the ignition off.
2. Disconnect the Cluster C1 harness connector.
3. Measure the resistance of the (K77) Transfer Case Position Sensor Input circuit between the Transfer Case Selector Switch harness connector and the Cluster C1 harness connector.

Is the resistance greater than 5.0 Ohms?

Yes

- Repair the (K77) Transfer Case Position Sensor Input circuit for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 5

5. (K977) MODE SELECT CIRCUIT OPEN
1. Measure the resistance of the (K977) Mode Select circuit between the Transfer Case Selector Switch harness connector and the Cluster C2 harness connector.

Is the resistance above 5.0 Ohms?

Yes

- Repair the (K977) Mode Select circuit for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Replace the Cluster. Instrument Cluster - Removal.
- Perform the BODY VERIFICATION TEST. Body Verification Test.