Test conditions
- Vehicle equipped with approved wheel and tire sizes, which must be the same on all four wheels. All tire inflation pressures checked according to specifications.
- Mechanical and hydraulic parts of brake system in good condition; no leaks in hydraulic lines and connections (visually inspect ABS Hydraulic Unit, brake calipers, tandem master brake cylinder).
- Wheel bearings and wheel bearing play OK
See SUSPENSION - FRONT or SUSPENSION - REAR .
- Wheel speed sensors installed correctly
See ANTILOCK BRAKE SYSTEM .
- Supply voltage must be OK (not less than 10.0 volts).
- Parking brake released
- Harness connector on ABS Control Module (w/EDL) -J104- properly connected, with retainer catch engaged.
- The OBD sequence can only be started with the vehicle stationary and the ignition switched on (or with the engine running). The diagnosis cannot be started if wheel speed exceeds 2.75 km/h (1.75 MPH), and will be terminated if the speed exceeds 20 km/h (13 MPH).
- While testing the ESP system, make sure that the vehicle's electrical system is not subjected to electromagnetic interference; keep the vehicle away from equipment with a high current draw such as electric welding units.