Test A

Pinpoint Test A: The Vehicle Does Not Operate Correctly In 4x4 Auto And 4x4 High Modes

Normal Operation

With the key in the ON position, the four wheel drive (4WD) control module receives the operators choice of 4WD selection from the 4WD mode select switch (MSS). The 4WD control module then controls the electric clutch and shift motor. If the transfer case is not responding to the operators intentions, systematically check all inputs and outputs to the 4WD control module. Check all circuits for opens and shorts to ground.

Possible Causes


- 4WD MSS

- 4WD control module

- 4WD indicator

- circuit 359 (GY/RD)

- circuit 780 (DB)

- transfer case electric clutch

- circuit 779 (BN)

- circuit 976 OG

- circuit 357 (YE/WH)

- circuit 3126 (TN/YE) (stability assist only)

- circuit 3125 (RD/YE) (stability assist only)

- circuit 774 (LG) (non-stability assist vehicles)

- OSS (non-stability assist vehicles) circuit 236 (BK/LG)

PINPOINT TEST A: THE VEHICLE DOES NOT OPERATE CORRECTLY IN 4X4 AUTO AND 4X4 HIGH MODES