Pinpoint Test 6: Vehicle Has No Or Inadequate Torque At Rear Wheels

PINPOINT TEST 6: VEHICLE HAS NO OR INADEQUATE TORQUE AT REAR WHEELS

Normal Operation

The on-demand four wheel drive (4WD) system uses data from other systems as inputs to the 4X4 control module. The 4X4 control module uses the inputs to determine the appropriate duty cycle to send to the active torque coupling (ATC) solenoid (part or rear axle) that delivers the desired torque to the rear wheels. If the 4X4 control module loses communication with, or receives invalid data from any of the necessary modules, DTCs are set and the 4X4 control module may not allow 4WD operation.

- DTC P1824 (4WD Clutch Relay Circuit Failure) - sets when the 4X4control module detects a short to ground on the active torque coupling (ATC) solenoid feedback circuit.
- DTC P1825 (4WD Clutch Relay Open Circuit) - sets when the 4X4 control module detects an open or a short to ground on the ATC solenoid command or feedback circuit for more than 2 seconds.

Possible Causes
- Tire(s)/axle out-of-range
- ATC solenoid (part of rear axle)
- 4X4 control module
- Power transfer unit (PTU)
- Wiring, terminals or connectors

Diagnostic Procedure

NOTE:Carry out Steps 1-10 outlined in Inspection and Verification prior to carrying out this test. See Initial Inspection and Diagnostic Overview.

Step 1-Step 4:

Step 5-Step 8:

Step 9: