Operation CHARM: Car repair manuals for everyone.

System Diagnosis

Theft Deterrent System Operational Flow Chart:






Before using the diagnostic charts, check the following inter-related electrical components for proper operation:
1. Horns
2. Exterior lamps
3. Trunk and door lock adjustments
4. Exterior door lock circuits Some system malfunctions do not affect the operation of the telltale light. Therefore, a complete testing of proper alarm function is required to detect some problems.



THEFT DETERRENT DIAGNOSIS

COMPLAINT: System totally inoperative.

PROBABLE CAUSE: Loose connectors at controller module to instrument panel harness or instrument panel harness to body harness.

CORRECTION: Repair or replace as needed.

PROBABLE CAUSE: Open in one of the following wires:
1. Ground wire (black) from controller (cavity A).
2. Battery feed. (cavity N)
3. Electric door lock wire.
4. Blown fuses.
5. Malfunctioning controller.

CORRECTION: Repair or replace as needed. Replace controller after investigating previously listed causes.

COMPLAINT: Inoperative horn and/or headlamps, and/or marker lamps in alarm mode.

PROBABLE CAUSE: Check for power at cavities A, C, and D at theft deterent relay.

CORRECTION: If no power, repair open. If power, replace relay.

COMPLAINT: Unable to reverse arming procedure with "UNLOCK" switch.

PROBABLE CAUSE: Open in door "UNLOCK" wire circuit.

CORRECTION: Inspect circuit from door lock to control module, Pin M.

PROBABLE CAUSE: Malfunctioning controller.

CORRECTION: Replace after investigating previously listed causes.

COMPLAINT: "Security System" tell tale light inoperative.

PROBABLE CAUSE: Check "ltr" fuse. Check bulb. Check wiring to bulb for shorts or open condition.

COMPLAINT: System operates normally except does not disarm at one or both doors.

PROBABLE CAUSE:

A. Try to disarm system by opening other door lock with key. If system disarms, check for:
1. Open light green wire to problem door.
2. Malfunctioning door key lock switch.
3. Open ground wire inside door.

B. If system cannot be disarmed from either door:
1. Check for open at LT GRN. wire at controller with door lock cylinder in unlock position.
2. Malfunctioning control module.

CORRECTION: Repair or replace as needed. Replace after investigating previous causes.


COMPLAINT: Security light will not go out upon closing doors and system will not arm.

PROBABLE CAUSE: Lock cylinder violated or unwanted ground at door jamb switch, driver seat switch, door and trunk tamper switches or pinched wires leading to these components.

CORRECTION: Check for unwanted ground in grn/drk wire (cavity D) from controller to lighter. Repair as necessary.

PROBABLE CAUSE: Door and trunk lock tamper switches out of adjustment.

CORRECTION: Readjust or replace as necessary.

PROBABLE CAUSE: Open in one of the following ground circuits: 150, 159, 262, and 263.

CORRECTION: Repair open.


COMPLAINT: Alarm activates when depressing door lock button when equipped with illuminated lock cylinder option.

PROBABLE CAUSE: Unwanted ground at door jamb switch.

CORRECTION: Remove wires from door jamb switch and install wires so that illuminated lock cylinder feed is separated from theft deterent wiring.

COMPLAINT: Alarm activates by itself.

PROBABLE CAUSE: Be sure alarm was not triggered by someone or something moving into the drivers seat when the system is armed.

CORRECTION: Inform owner of the presence of the drivers seat switch, the proper operation of the system.

PROBABLE CAUSE: Check for too close adjustment of door jamb switches.

CORRECTION: Readjust or replace as necessary.

COMPLAINT: System cannot be armed. Tell-tale light OK.

PROBABLE CAUSE: Check for open in circuit 261 or 262.

CORRECTION: Repair open.

COMPLAINT: Key buzzer activated by all doors.

PROBABLE CAUSE: Diode shorted.

CORRECTION: Replace diode.

COMPLAINT: Vehicle cannot be started.

PROBABLE CAUSE: Pin 2 at starter interrupt relay (coil ground) grounded.

CORRECTION: Repair short to ground.

PROBABLE CAUSE: Pin 3 at starter interrupt relay (to starter) open.

CORRECTION: Repair open in circuit 6 purple wire.

PROBABLE CAUSE: Starter interrupt relay Pin E at controller (starter interrupt control) grounded.

CORRECTION: Reinstall relay. Repair short to ground.