J2 Check ABS Valve Operation

- Turn air suspension compressor switch OFF.

- Turn ignition switch to the OFF position.

Anti-Lock Module:

- Disconnect 55-pin plug from anti-lock brake control module.

Break Out Box:

- Connect Rotunda EEC-IV breakout box 014-00322 with Anti-Lock Test Adapter T90P-50-ALA or equivalent to the anti-lock 55-pin connector on wire harness.

- Lift vehicle and rotate wheels to ensure they turn freely.

- Jump pins 19 and 34 at breakout box.

- Short pins 20, 2 and 60 to each other at breakout box.

- Apply moderate brake pedal effort and check that LH front wheel will not turn.

- Check to see that LH front wheel turns freely when ignition switch is in the ON position.

- Turn air suspension compressor switch ON when vehicle is off hoist.

CAUTION: Do not leave ignition switch in the ON position for more than one minute, or valve damage may result.

- Does wheel turn freely?

YES -- Turn ignition switch to the OFF position. Disconnect wire leads. Go to J3. J3 Check ABS Operation RH Front Wheel

NO -- Verify correct wiring between 55-pin connector and 19-pin connector on brake pressure control valve block. If wiring is correct, replace brake pressure control valve block.