J2 Check ABS Valve Operation

- Turn air suspension OFF.

- Turn ignition switch OFF.

Anti-Lock Module:

- Disconnect anti-lock brake wiring from ABS module.

Breakout Box:

- Connect EEC-IV Breakout Box 014-00322 with Anti-Lock Test Adapter T90P-50-ALA to the anti-lock 55-pin connector on anti-lock brake wiring 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 RUN.

- Turn air suspension ON when vehicle is off hoist.

CAUTION: Do not leave ignition switch in RUN on for more than 1 minute, or valve damage may result.

- Do wheels turn freely?

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

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