4WD HI Indicator Short to Ground

4WD HI INDICATOR SHORT TO GROUND





For a complete wiring diagram refer to diagrams.
^ When Monitored:
Continuously with the ignition on.
^ Set Condition:
The Transfer Case Control Module detects a short to ground on the (G91) 4WD High Indicator circuit.

Possible Causes

- INTERMITTENT 4WD HI INDICATOR SHORT TO GROUND
- (G91) 4WD HIGH INDICATOR CIRCUIT OPEN
- (G91) 4WD HIGH INDICATOR CIRCUIT SHORT TO GROUND
- (G91) 4WD HIGH INDICATOR CIRCUIT SHORT TO VOLTAGE
- TRANSFER CASE SELECTOR SWITCH
- TRANSFER CASE CONTROL MODULE

1. 4WD HI INDICATOR SHORT TO GROUND 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 Selector Switch to each position.
With the DRBIII read Transfer Case DTCs.

Does the DRBIII display 4WD HI INDICATOR SHORT TO GROUND?
Yes >>Go To 2
No >>Go To 7

2. (G91) 4WD HIGH INDICATOR 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 (G91) 4WD High Indicator circuit from the Transfer Case Control Module C1 harness connector to the Transfer Case Selector Switch harness connector.

Is the resistance above 5.0 ohms?
Yes >>Repair the (G91) 4WD High Indicator circuit for an open.
Perform TRANSFER CASE VERIFICATION TEST.Transfer Case Verification Test
No >>Go To 3

3. (G91) 4WD HIGH INDICATOR CIRCUIT SHORT TO GROUND





Measure the resistance between ground and the (G91) 4WD High Indicator circuit.

Is the resistance below 5.0 ohms?
Yes >>Repair the (G91) 4WD High Indicator circuit for a short to ground.
Perform TRANSFER CASE VERIFICATION TEST.Transfer Case Verification Test
No >>Go To 4

4. (G91) 4WD HIGH INDICATOR CIRCUIT SHORT TO VOLTAGE





Ignition on, engine not running.
Measure the voltage of the (G91) 4WD High Indicator circuit.

Is the voltage above 0.5 volt?
Yes >>Repair the (G91) 4WD High Indicator circuit for a short to voltage.
Perform TRANSFER CASE VERIFICATION TEST.Transfer Case Verification Test
No >>Go To 5

5. TRANSFER CASE SELECTOR SWITCH





Turn the ignition off to the lock position.
Connect the Transfer Case Control Module C1 harness connector. Ignition on, engine not running.
With a 12-volt test light connected to B+, check the (G91) 4WD High Indicator circuit in the Transfer Case Selector Switch harness connector.

NOTE: The test light should not be illuminated. With the DRBIII actuate the 4HI LED.
With a 12-volt test light connected to B+, check the (G91) 4WD High
Indicator circuit in the Transfer Case Selector Switch harness connector.

NOTE: The test light should be illuminated during the actuation.

Does the test light illuminate when the circuit is actuated and remain off otherwise?
Yes >>Replace the Transfer Case Selector Switch in accordance with the Service Information.
Perform TRANSFER CASE VERIFICATION TEST.Transfer Case Verification Test
No >>Go To 6

6. 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 Charging System related DTCs or 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

7. 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.