C2109

C2109-DRIVETRAIN SUPPLY VOLTAGE CIRCUIT LOW





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

Possible Causes
FRONT DIFFERENTIAL SOLENOID
REAR DIFFERENTIAL SOLENOID
(T301) SWITCHED BATTERY SOLENOID SUPPLY CIRCUIT SHORTED TO GROUND
FDCM

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

2. FRONT DIFFERENTIAL SOLENOID
Turn the ignition off.
Disconnect the Front Differential Solenoid harness connector.
Turn the ignition on.
With the DRBIII(R), actuate the Front Differential Solenoid.
Measure the voltage of the (T301) Switched Battery Solenoid Supply circuit in the Front Differential Solenoid harness connector.
Is the voltage 12 volts?
Yes >>Inspect the Front Differential Solenoid Jumper harness, repair/replace as necessary. If OK, replace the Front Differential Solenoid. Perform FDCM VERIFICATION TEST. FDCM Verification Test
No >>Go To 3

3. REAR DIFFERENTIAL SOLENOID
Turn the ignition off.
Disconnect the Rear Differential Solenoid harness connector.
Turn the ignition on. With the DRBIII(R), actuate the Rear Differential Solenoid.
Measure the voltage of the (T301) Switched Battery Solenoid Supply circuit in the Rear Differential Solenoid harness connector.
Is the voltage 12 volts?
Yes >>Inspect the Rear Differential Solenoid Jumper harness, repair/replace as necessary. If OK, replace the Rear Differential Solenoid. Perform FDCM VERIFICATION TEST. FDCM Verification Test
No >>Go To 4

4. (T301) SWITCHED BATTERY SOLENOID SUPPLY CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the FDCM harness connector.
Measure the resistance of the (T301) Switch Battery Solenoid Supply circuit at the FDCM harness connector.
Is the resistance below 1ohms?
Yes >>Repair the short to ground in the (T301) Switch Battery Solenoid Supply circuit. Perform FDCM VERIFICATION TEST. FDCM Verification Test
No >>Go To 5

5. 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. FDCM Verification Test
No >>Replace and program the Final Drive Control Module.
Perform FDCM VERIFICATION TEST. FDCM Verification Test

6. 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(R), 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. FDCM Verification Test
No >>Test Complete.