THEFT DETERRENT SYSTEM DIAGNOSIS PROCEDURE

THE 1981 DIAGNOSIS AND SERVICE PROCEDURES HAVE BEEN CHANGED FOR VEHICLES EQUIPPED WITH THEFT DETERRENT. OUTLINED ON THE FOLLOWING PAGES ARE DIAGNOSIS CHECKS FOR THE CONTROLLER AND RELAY AS WELL AS UPDATED WIRING SCHEMATICS. CONTROLLER CHECKS: CONTROLLER HARNESS DISCONNECTED (SEE FIGURE 1) 1.CONNECT A ONE (1) CANDLEPOWER TEST LIGHT TO THE "N" (RED/WHITE) WIRE AND A SUITABLE GROUND. TEST LIGHT SHOULD LIGHT, INDICATING POWER SUPPLY TO THE HORNS. 2.CONNECT A TEST LIGHT BETWEEN THE "M" (PINK) WIRE AND A SUITABLE GROUND. THE LIGHT SHOULD COME ON ONLY WHEN THE ELECTRIC DOOR LOCK SWITCH IN THE ARMREST IS MOVED TO THE "UNLOCK" POSITION. 3.CONNECT A TEST LIGHT BETWEEN THE "K" (PINK/DOUBLE BLACK)*WIRE AND GROUND. TEST LIGHT SHOULD LIGHT ONLY WHEN THE IGNITION SWITCH IS TURNED "ON". IF NOT, CHECK FOR BAD IGNITION FUSE IN FUSE BLOCK. 4.CONNECT A TEST LIGHT BETWEEN THE "J" (LIGHT BLUE) WIRE AND ANY 12V POWER SUPPLY. THE LIGHT SHOULD COME ON TO FULL BRIGHTNESS ONLY IF A DOOR IS OPENED. IF IT COMES ON WHEN THE DOORS ARE CLOSED, A DOOR OR TRUNK LOCK CYLINDER MAY HAVE BEEN TAMPERED WITH. 5.CONNECT TEST LIGHT BETWEEN "H" (LIGHT GREEN) WIRE AND 12V POWER SUPPLY. TEST LIGHT SHOULD COME ON TO FULL BRIGHTNESS ONLY WHEN THE OUTSIDE DOOR KEY IS TURNED TO THE UNLOCK POSITION. 12V TO "H" WIRE AND DOOR LOCKS SHOULD CYCLE. 6.CONNECT A TEST LIGHT FROM THE "G" (YELLOW) WIRE TO A SUITABLE GROUND. THE LIGHT SHOULD COME ON WHILE THE ELECTRIC DOOR LOCK SWITCH IS BEING ACTIVATED, INDICATING POWER TO THE ELECTRIC DOOR LOCK SWITCHES. TEST LIGHT SHOULD LIGHT IN "LOCK" POSITION, AND GO OFF IN THE "UNLOCK" POSITION. 7.WITH RELAY HARNESS INSTALLED IN CONTROL RELAY, CONNECT TEST LIGHT BETWEEN THE "F" (BLACK/WHITE) WIRE AND GROUND. HORN SHOULD SOUND AND LIGHTS SHOULD COME ON. 8.WITH THE KEY ON, A TEST LIGHT CONNECTED BETWEEN THE "E" (LIGHT BLUE) WIRE AND GROUND SHOULD MAKE THE RELAY CYCLE. 9.CONNECT A JUMPER WIRE FROM THE "D" (DARK GREEN) WIRE TO A SUITABLE GROUND. THE SECURITY WARNING LAMP SHOULD COME ON. 10.CONNECT A TEST LIGHT BETWEEN THE "A" (BLACK) WIRE AND A 12V POWER SOURCE. THE LAMP SHOULD COME ON, INDICATING THAT THE SYSTEM IS PROPERLY GROUNDED. *WHITE FOR "A" SERIES. RELAY CHECKS: RELAY HARNESS DISCONNECTED (SEE FIGURE 2) 1.CONNECT A JUMPER WIRE BETWEEN THE "A" (RED) AND "B" (DARK GREEN) WIRE CONNECTORS. HORNS SHOULD SOUND, INDICATING POWER TO THE HORNS, AND A COMPLETE HORN CIRCUIT TO GROUND. 2.CONNECT A JUMPER WIRE BETWEEN THE "D" (RED) AND "C" (DARK BROWN) WIRE CONNECTORS. PARK, TAIL, AND SIDE MARKER LIGHTS SHOULD COME ON. 3.CONNECT A JUMPER WIRE BETWEEN THE "D" (RED) AND "E" (TAN) WIRE CONNECTORS. LOW BEAM HEADLIGHTS SHOULD COME ON. 4.WITH THE RELAY HARNESS CONNECTED, JUMP FROM "F" (BLACK/WHITE) TO GROUND. RELAY SHOULD "CLICK" (CLOSE) AND ACTIVATE LIGHTS AND HORN CIRCUITS.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.