C1401

C1401- TRANSFER CASE RANGE SELECT SWITCH CIRCUIT LOW





For a complete wiring diagram refer to Diagrams/Electrical. Electrical Diagrams


- When Monitored:

With the ignition on.

- Set Condition:

Transfer Case Range Select Switch voltage less than 0.1568 volts for 5 seconds






Diagnostic Test


1. TRANSFER CASE SWITCH VOLTAGE LESS THAN 0.2 VOLTS

Ignition on, engine not running.

With the scan tool under CCN, read the Transfer Case Switch voltage.

Is the voltage less than 0.2 volts?

Yes

- Go To 2

No

- Go To 8


2. (K77) 5 VOLT SELECTOR SWITCH SUPPLY CIRCUIT VOLTAGE LESS THAN 0.2 VOLTS





Turn the ignition off to the lock position.

Disconnect the Transfer Case Selector Switch harness connector.

Ignition on, engine not running.

Measure the voltage of the (K77) 5 Volt Selector Switch Supply circuit.

Is the voltage less than 0.2 volts?

Yes

- Go To 3

No

- Go To 5



3. (K77) 5 VOLT SELECTOR SWITCH SUPPLY CIRCUIT OPEN





Turn the ignition off to the lock position.

Disconnect the Cluster C4 connector.

Measure the resistance of the (K77) 5 Volt Selector Switch Supply circuit between the Instrument Cluster C4 harness connector and the Transfer Case Selector Switch harness connector.

Is the resistance greater than 5.0 ohms?

Yes

- Repair the (K77) 5 Volt Selector Switch Supply circuit for an open.
- Perform the TRANSFER CASE VERIFICATION TEST-VER 1. Verification Tests

No

- Go To 4


4. (K77) 5 VOLT SELECTOR SWITCH SUPPLY CIRCUIT SHORTED TO GROUND





Measure the resistance between ground and the (K77) 5 Volt Selector Switch Supply circuit.

Is the resistance less than 5.0 ohms?

Yes

- Repair the (K77) 5 Volt Selector Switch Supply circuit for a short to ground.
- Perform the TRANSFER CASE VERIFICATION TEST-VER 1. Verification Tests

No

- Replace the Instrument Cluster.
- Perform the BODY VERIFICATION TEST-VER 1 and TRANSFER CASE VERIFICATION TEST-VER 1. Verification Tests



5. TRANSFER CASE SELECTOR SWITCH





Turn the ignition off to the lock position.

Connect a jumper wire between the (K77) 5 Volt Selector Switch Supply circuit and the (K977) Mode Select circuit in the Transfer Case Selector Switch harness connector.

Ignition on, engine not running.

With the scan tool in Data Display, read the Range Switch voltage.


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

Does the voltage display as described?

Yes

- Replace the Transfer Case Selector Switch.
- Perform the TRANSFER CASE VERIFICATION TEST-VER 1. Verification Tests

No

- Go To 6



6. (K977) MODE SELECT CIRCUIT SHORT TO GROUND





Disconnect the Cluster C3 connector.

Measure the resistance between ground and the (K977) Mode Select circuit.

Is the resistance less than 5.0 ohms?

Yes

- Repair the (K977) Mode Select circuit for a short to ground.
- Perform the TRANSFER CASE VERIFICATION TEST-VER 1. Verification Tests

No

- Go To 7



7. (K977) MODE SELECT CIRCUIT OPEN





Measure the resistance of the (K977) Mode Select circuit between the Cluster C3 harness connector and the Transfer Case Selector Switch harness connector.

Is the resistance above 5.0 ohms?

Yes

- Repair the (K977) Mode Select circuit for an open.
- Perform the TRANSFER CASE VERIFICATION TEST-VER 1. Verification Tests

No

- Replace the Instrument Cluster.
- Perform the BODY VERIFICATION TEST-VER 1 and TRANSFER CASE VERIFICATION TEST-VER 1. Verification Tests



8. INTERMITTENT WIRING AND CONNECTORS

The conditions necessary to set this DTC are not present at this time.

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.

While monitoring the scan tool data relative to this circuit, wiggle test the wiring and connectors.

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-VER 1. Verification Tests

No

- Test complete.