Test Prerequisites For OBD

Test prerequisites for OBD
^ 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 lines and connections not leaking (visual check of hydraulic unit, brake calipers, wheel cylinders, tandem master brake cylinder).
^ ABS Control Module (w/EDL) -J104- is correctly bolted to ABS Hydraulic Unit -N55-.
^ Connector on ABS Control Module (w/EDL) -J104- correctly plugged-in (retainer is engaged).
^ Check contacts of ABS components for damage and correct seating.
^ All fuses according to wiring diagram OK (remove fuse from fuse 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).
^ Wheel bearings and wheel bearing play are OK.
^ 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 away from equipment with a high current draw, e.g. from an electric welding module.