Rear Antilock Brakes (RABS)
J7 VERIFY PROPER RABS OPERATIONWARNING: PERFORM THIS TEST ON AN AXLE HOIST ONLY.
WARNING: THE ELECTRICAL POWER TO THE AIR SUSPENSION SYSTEM MUST BE SHUT OFF PRIOR TO HOISTING, JACKING OR TOWING AN AIR SUSPENSION VEHICLE. THIS CAN BE ACCOMPLISHED BY TURNING OFF THE AIR SUSPENSION SWITCH LOCATED IN THE RH KICK PANEL AREA. FAILURE TO DO SO MAY RESULT IN UNEXPECTED INFLATION OR DEFLATION OF THE AIR SPRINGS WHICH MAY RESULT IN SHIFTING OF THE VEHICLE DURING THESE OPERATIONS.
NOTE: Because vehicle is not on the ground, the wheels will spin for a significant time. This is not indicative of vehicle braking performance.
- Key "OFF".
- Raise and support the vehicle on an axle hoist so that all wheels are clear of the ground.
- Key "ON".
- Place the vehicle transmission in drive low (automatic) or first gear (manual).
- Accelerate to 16 Kph (10 mph).
- Press hard on the brake pedal until wheels stop.
- Do the rear wheels first lock up and then spin?
> Yes
Reactivate the air suspension system. Repeat System Pre-Check. Initial Inspection and Diagnostic Overview
> No
Replace the anti-lock electronic control module. Reactivate the air suspension system. Go to Pinpoint Test S. [1][2]Pinpoint Tests