780 V6-2849cc 2.8L SOHC B280F (1987)
1.
Sensor(s) incorrectly fitted or insecurely mounted.
2.
Oxidized or poorly-made wiring connections.
3.
Faulty sensor(s).
4.
Physical activation of vibration sensors (i.e. intentional activation).
Note:
On cars equipped with catalytic converters, a clicking sound caused by thermal stresses may be heard from the converter casing when the car has
stopped. In some cases, the clicks may be sufficiently strong to activate the vibration sensors, producing a false alarm.
One means of overcoming this problem may be to place a thin (approx. 1 mm) layer of absorbent plastic or rubber between the sensor and body.
If the problem persists despite this action, the sensor must be disconnected/removed and the associated loop short-circuited. (This is done by joining the
black and red leads.)
Initially, disconnection/removal of the sensor should be carried out only on the right-hand side, where the distance between the catalytic converter and
sensor is least.
Fault in magnetic switch loop (hood and trunk lid/tailgate).
1.
Magnetic switches incorrectly installed.
2.
Magnetic switches damaged mechanically or electrically.
3.
Oxidized or poorly-made wiring connections.
Fault in door switch loop
1.
Door switches dirty and conducting current, particularly in damp weather.
2.
Pinched wiring causing sporadic ground connection.
