C2109

C2109-DRIVETRAIN SUPPLY VOLTAGE CIRCUIT LOW

Wiring Diagram:

- When Monitored:
Ignition on.
- Set Condition:
The FDCM recognizes the Switched Battery Solenoid Supply circuit voltage is too low.

Possible Causes
- (T301) SWITCHED BATTERY SOLENOID SUPPLY CIRCUIT OPEN
- (T301) SWITCHED BATTERY SOLENOID SUPPLY CIRCUIT SHORTED TO GROUND FDCM
- FRONT DIFFERENTIAL SOLENOID
- REAR DIFFERENTIAL SOLENOID
- TRANSFER CASE MOTOR
- FINAL DRIVE CONTROL MODULE (FDCM)

Diagnostic Test
1. ACTIVE DTC
Ignition on, engine not running. With a scan tool, read DTCs.
Is the DTC active at this time?
Yes >> Go To 2
No >> Go To 6

2. (T301) SWITCHED BATTERY SOLENOID SUPPLY CIRCUIT OPEN

Turn the ignition off.
Disconnect the FDCM C1 harness connector.
Disconnect the Transfer Case Motor harness connector.
Measure the resistance of the (T301) Switch Battery Solenoid Supply circuit between the FDCM C1 harness connector and the Transfer Case Motor harness connector.

Is the resistance below 100 ohms?

Yes

Go To 3

No

- Repair the open in the (T301) Switch Battery Solenoid Supply circuit.
- Perform FDCM VERIFICATION TEST.

3. (T301) SWITCHED BATTERY SOLENOID SUPPLY CIRCUIT SHORTED TO GROUND

Disconnect the Front Differential Solenoid harness connector.
Disconnect the Rear Differential Solenoid harness connector.
Measure the resistance between ground and the (T301) Switch Battery Solenoid Supply circuit in the FDCM C1 harness connector.

Is the resistance below 100 ohms?

Yes

- epair the short to ground in the (T301) Switch Battery Solenoid Supply circuit.
- Perform FDCM VERIFICATION TEST.

No

- Go To 4


4. FRONT DIFFERENTIAL SOLENOID OPEN

Measure the resistance of the Front Differential Solenoid at the component side.

Is the resistance above 50 ohms?

Yes
- Inspect the Front Differential Solenoid jumper harness connector, repair/replace as necessary. If OK, replace the shorted Front Differential Solenoid in accordance with the Service Information.
- Perform FDCM VERIFICATION TEST.

No
- Go To 5

5. REAR DIFFERENTIAL SOLENOID OPEN

Measure the resistance of the Front Differential Solenoid at the component side.

Is the resistance above 50 ohms?

Yes
- Inspect the Rear Differential Solenoid jumper harness connector, repair/replace as necessary. If OK, replace the shorted Rear Differential Solenoid in accordance with the Service Information.
- Perform FDCM VERIFICATION TEST.

No
- Go To 6


6. TRANSFER CASE MOTOR OPEN

Measure the resistance of the Transfer Case Motor at the component side.

Is the resistance above 50 ohms?

Yes
- Replace the shorted Transfer Case Motor in accordance with the Service Information.
- Perform FDCM VERIFICATION TEST.

No
- Go To 7

7. FDCM

NOTE: Before continuing, check the FDCM harness connector terminals for corrosion, damage, or terminal push out.

Repair as necessary. Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.
Were there any problems found?
Yes >> Repair as necessary Perform FDCM VERIFICATION TEST.
No >> Replace and program the Final Drive Control Module . Perform FDCM 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 FDCM VERIFICATION TEST.
No >> Test Complete.