On Board Diagnostic (OBD), Test Requirements

^ Permissible tire size for all wheels/tires; inflated to specified tire pressure.
^ Conventional brake system with brake light switch and brake lights OK
^ Hydraulic lines and connections not leaking (visual check at hydraulic unit, brake calipers, wheel brake cylinders, tandem brake master cylinder).
^ Wheel bearings and wheel bearing play OK
^ Installed positions of wheel speed sensors OK
^ Control module bolted correctly to hydraulic unit.
^ Connector at control module -J104- correctly inserted (lock is latched).
^ Connector contacts of ABS components checked for damage and correct positioning.
^ All fuses OK (to check fuses, remove from fuse box) - Electrical Wiring Diagrams, Troubleshooting & Component Locations binder
^ Supply voltage at least 10.0 Volts.
^ Vehicle at a standstill and ignition switched on (or engine running). Initiation of On Board Diagnostic is only possible under these conditions. At a wheel speed greater than 2.75 km/h On Board Diagnostic is not possible. If a speed of 20 km/h is exceeded, On Board Diagnostic is discontinued.
^ Vehicle electronics must not be affected by electromagnetic influences during checking of ABS/EDL or ATC - keep the vehicle away from tools with strong current consumption, e.g. an electric welding tool.