Pinpoint Test L: C0688:09, C0688:11, C0688:12, C0688:19, C0688:1D, C0688:72, C0688:74, C0688:A2
- Refer to FOUR WHEEL DRIVE SYSTEMS
for schematic and connector information.
Normal Operation and Fault Conditions
The transfer case clutch actuator is a reversible DC motor. When front axle torque is required, the actuator motor rotates clockwise to engage a ball-ramp device. When no torque is required, the motor rotates counter-clockwise to the kiss point position. If an AWD fault is detected, the AWD module may hold the actuator motor position, attempt full clutch release, or attempt full clutch apply.
Each time the AWD module wakes up, it will command the transfer case clutch actuator counter clockwise to the hard stop position, clockwise to the soft stop, and back to the kiss point position. If needed, it will adjust the previous kiss point position to the new learned position.
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition AWD P0641:1C Sensor Reference Voltage "A" Circuit/Open: Circuit Voltage Out Of Range Sets when the AWD module detects Sensor Reference Voltage "A" Circuit/Open with circuit voltage out of range. AWD C0688:09 4WD/AWD Clutch "A" Brake Actuator: Component Failures Sets when the AWD module detects Clutch "A" Brake actuator component failure. AWD C0688:11 4WD/AWD Clutch "A" Brake Actuator: Circuit Short To Ground Sets when the AWD module detects Clutch "A" Brake actuator Circuit short to ground. AWD C0688:12 4WD/AWD Clutch "A" Brake Actuator: Circuit Short To Battery Sets when the AWD module detects Clutch "A" Brake actuator circuit short to battery. AWD C0688:19 4WD/AWD Clutch "A" Brake Actuator: Circuit Current Above Threshold Sets when the AWD module detects Clutch "A" Brake actuator circuit current above threshold. AWD C0688:1D 4WD/AWD Clutch "A" Brake Actuator: Circuit Current Out Of Range Sets when the AWD module detects Clutch "A" Brake actuator circuit current out of range. AWD C0688:72 4WD/AWD Clutch "A" Brake Actuator: Actuator Stuck Open Sets when the AWD module detects Clutch "A" Brake actuator circuit actuator stuck open. AWD C0688:74 4WD/AWD Clutch "A" Brake Actuator: Actuator Slipping Sets when the AWD module detects Clutch "A" Brake actuator circuit actuator slipping. AWD C0688:A2 4WD/AWD Clutch "A" Brake Actuator: System Voltage Low Sets when the AWD module detects Clutch "A" Brake actuator circuit system voltage low. Possible Sources
- Transfer case clutch actuator brake control "A" sensor faults
- Loose AWD module case ground connection
- Transfer case clutch actuator brake control "A" shorted to ground
- Transfer case clutch actuator brake control "A" position sensor Circuit Short To Battery
- Transfer case clutch actuator brake control "A" position sensor Circuit Current Above Threshold
- Transfer case clutch actuator brake control "A" Circuit Current Out of Range
- Transfer case clutch actuator brake control "A" Circuit System Voltage Low
- Transfer case clutch actuator brake control "A" Actuator Stuck Open
- Transfer case clutch actuator brake control "A" Actuator Slipping
- Transfer case
- L1 CHECK FOR TRANSFER CASE CLUTCH "A" BRAKE ACTUATOR POSITION SENSOR FAULTS
- Review DTC retrieved from AWD module continuous memory self-test.
Are any transfer case clutch actuator position sensor DTC stored in memory?
Yes RESOLVE all transfer case clutch "A" actuator position sensor DTC first. No GO to L2 - L2 CHECK THE AWD MODULE GROUND
- Disconnect AWD module connector C2371.
- Ignition ON.
- Measure:
Positive Lead Measurement / Action Negative Lead C2371-46 Ground
Is the resistance less than 3 ohms?
Yes If less than 3 ohms, replace the AWD module. REFER to: All-Wheel Drive (AWD) Module . No If greater than 3 ohms, repair ground circuit. GO to L3 - L3 CHECK THE TRANSFER CASE CLUTCH "A" BRAKE ACTUATOR CIRCUITS FOR SHORT TO GROUND
- Disconnect the AWD module connector C2371.
- Inspect harness connector for damage. Verify terminals are not splayed, damaged, or pushed out of the connector.
- Disconnect the transfer case connector C2370.
- Inspect harness connector for damage. Verify terminals are not splayed, damaged, or pushed out of the connector.
- Measure:
Positive Lead Measurement / Action Negative Lead C2371-3 Ground C3841-2 Ground
Are the resistances greater than 10, 000 ohms?
Yes GO to L4 No REPAIR the short to ground. - L4 CHECK THE TRANSFER CASE CLUTCH "A" BRAKE ACTUATOR CIRCUITS FOR HIGH RESISTANCE
- Disconnect the AWD module connector C3841.
- Disconnect the transfer case clutch actuator connector C2370.
Are the resistances less than 3 ohms?
Yes GO to L5 No REPAIR the open circuit. - L5 CHECK THE TRANSFER CASE CLUTCH "A" BRAKE ACTUATOR CIRCUITS FOR A SHORT TOGETHER
- Disconnect the AWD module connector C2371.
- Disconnect the transfer case clutch actuator connector C2370.
Is the resistance greater than 10, 000 ohms?
Yes GO to L6 No REPAIR the short circuit. - L6 CHECK TRANSFER CASE REDUCTION GEARSET
- Remove transfer case clutch "A" brake actuator.
- Manually turn transfer case clutch shaft counter clockwise to hard stop.
- Rotate actuator shaft clockwise to soft stop. It may take up to 25 turns stop to stop.
Does the clutch shaft hit both stop points as described?
Yes INSTALL a new transfer case clutch actuator. REFER to: Transfer Case Shift Motor . No INSTALL a new transfer case. REFER to: Transfer Case - Removal and Transfer Case - Installation .