Transfer Case Selector Switch Error

TRANSFER CASE SELECTOR SWITCH ERROR





For a complete wiring diagram refer to diagrams.
^ When Monitored:
Continuously with the ignition on.
^ Set Condition:
Whenever the Transfer Case Control Module detects any of the following errors:
1. Selector Switch input of less than 250 ohms or more than 14.5k ohms.
2. Selector Switch input voltage less than .25 volts or greater than 5.0 volts.

Possible Causes

- INTERMITTENT TRANSFER CASE SELECTOR SWITCH ERROR
- (K977) MODE SELECT CIRCUIT OPEN
- (K977) MODE SELECT CIRCUIT SHORT TO GROUND
- (K977) MODE SELECT CIRCUIT SHORT TO VOLTAGE
- (T322) 5 VOLT SELECTOR SWITCH SUPPLY CIRCUIT OPEN
- TRANSFER CASE SELECTOR SWITCH
- TRANSFER CASE CONTROL MODULE

1. TRANSFER CASE SELECTOR SWITCH ERROR DTC IS PRESENT
With the DRBIII read Transfer Case DTCs. Record all DTC information.
With the DRBIII erase Transfer Case DTCs.
Start the engine and move the Transfer Case Select Switch to each position.
With the DRBIII read Transfer Case DTCs.

Does the DRBIII display TRANSFER CASE SELECTOR SWITCH ERROR?
Yes >>Go To 2
No >>Go To 8

2. (K977) MODE SELECT CIRCUIT OPEN





Turn the ignition off to the lock position.
Disconnect the Transfer Case Control Module C1 harness connector.
Disconnect the Transfer Case Selector Switch harness connector.

NOTE: Note: Check connectors - Clean/repair as necessary.

Measure the resistance of the (K977) Mode Select circuit from the Transfer Case Control Module harness connector to 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 TRANSFER CASE VERIFICATION TEST. Transfer Case Verification Test
No >>Go To 3

3. (K977) MODE SELECT CIRCUIT SHORT TO GROUND





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

Is the resistance below 5.0 ohms?
Yes >>Repair the (K977) Mode Select circuit for a short to ground.
Perform TRANSFER CASE VERIFICATION TEST. Transfer Case Verification Test
No >>Go To 4

4. (K977) MODE SELECT CIRCUIT SHORT TO VOLTAGE





Ignition on, engine not running. Measure the voltage of the (K977) Mode Select circuit.

Is the voltage above 0.5 volt?
Yes >>Repair the (K977) Mode Select circuit for a short to voltage.
Perform TRANSFER CASE VERIFICATION TEST. Transfer Case Verification Test
No >>Go To 5

5. (T322) 5 VOLT SELECTOR SWITCH SUPPLY CIRCUIT OPEN





Turn the ignition off to the lock position.
Disconnect the Transfer Case Control Module C2 harness connector.
Measure the resistance of the (T322) 5 Volt Selector Switch Supply circuit from the Transfer Case Control Module C2 harness connector to the Transfer Case Selector Switch harness connector.

Is the resistance above 5.0 ohms?
Yes >>Repair the (T322) 5 Volt Selector Switch Supply circuit for an open.
Perform TRANSFER CASE VERIFICATION TEST. Transfer Case Verification Test
No >>Go To 6

6. TRANSFER CASE SELECTOR SWITCH





Connect the Transfer Case Select Switch harness connector.
Measure the resistance between the (T322) 5 Volt Selector Switch Supply circuit in the Transfer Case Control Module C2 harness connector and the (K977) Mode Select circuit in the Transfer Case Control Module C1 harness connector.

Is the resistance between 200 ohms and 15.5k ohms in all Selector Switch ranges?
Yes >>Go To 7
No >>Replace the Transfer Case Selector Switch in accordance with the Service Information.
Perform TRANSFER CASE VERIFICATION TEST. Transfer Case Verification Test

7. TRANSFER CASE CONTROL MODULE
Using the wiring diagram as a guide, inspect the wiring and connectors relative to this DTC. Inspect all power and ground circuits. Repair as necessary.
If there are no other possible causes remaining, view repair.

Repair
Replace the Transfer Case Control Module in accordance with the Service Information.
Perform TRANSFER CASE VERIFICATION TEST. Transfer Case Verification Test

8. INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
Wiggle test the wiring harness and connectors while checking for shorted and open circuits.
Using the DRBIII monitor the data related to this circuit while performing the wiggle test. Look for the data to change or for the DTC to reset.

Were there any problems found?
Yes >>Repair as necessary.
Perform TRANSFER CASE VERIFICATION TEST. Transfer Case Verification Test
No >>Test Complete.