OBD Test Prerequisites

OBD Test Prerequisites
^ The tires installed to all wheels must be of the same (approved) size; tires inflated to prescribed pressure.
^ Mechanical/hydraulic parts of the brake system including brake light switch and brake lights OK.
^ Hydraulic connections and lines are not leaking (visual check of hydraulic module, brake calipers, wheel cylinders, tandem brake master cylinder).
^ Wheel bearings and wheel bearing play are OK.
^ ABS Control Module J104 (w/EDL) is correctly bolted to ABS Hydraulic Unit N55
^ Electrical connection is installed correctly to the ABS Control Module J104 (w/EDL) (locking device is engaged correctly).
^ Check electrical connections of ABS components for damage and correct seating.
^ All fuses, according to wiring diagram OK. (remove fuse from holder to check).
^ Supply voltage OK. (at least 10.0 V)
^ Access to the OBD is only possible when the vehicle is stationary and ignition turned on (or engine running).
^ When checking the ABS system make sure that the vehicle electric system is not affected by electro-magnetic interference, i.e. the vehicle is kept well away from equipment with a high current draw, e.g. from an electric welding module.