General information
The operation of the system is based on the operation of individual lock activators for each of the car doors. The system consists of control switches, door actuators and connecting wiring. Diagnosis of system failures is limited to checking the condition of the contact connections of the electrical circuit and the correct operation of the door activators. Deeper checks should be entrusted to car service specialists. The single lock system control unit is located under the instrument panel, to the right of the fuse/relay mounting block.
The functioning of a single lock occurs due to the operation of bidirectional electromagnets located in the car doors. The control switch has two positions: LOCKED and OPEN. On models of recent years of production equipped with a remote control system, the switches give a signal to the control module, which, in turn, acts on electromagnetic switches or door lock motors. Depending on the initial position of the switch, the polarity of the power supply of the activators is reversed. On older models, the switches are connected directly to the door lock electromagnets.
On some models, the single lock system is combined with an anti-theft alarm system.
If it is not possible to find the cause of the failure during the checks described below, the car should be driven to a service station.
Examination
1. Always check the condition of the loop protection first. On some models, protection is provided by a combination of fuses and circuit breakers.
2. Toggle the control switches in both directions with the engine off. Listen for clicks as the electromagnets in the door activators actuate.
3. If there are no clicks, check the voltage supply to the switches. If the power supply is interrupted, check the condition of the wiring in the section of the circuit between the corresponding switch and the fuse mounting block. If power is supplied properly, check the condition of the switch (conductivity distribution).
4. Replace switches that are not conducting in both positions. If the switch is OK, but no relay clicks are heard, check the condition of the wiring between the relevant switch and the electromagnet. Make necessary repairs.
5. Check the condition of the grounding of the switches and the control box.
6. If only one of the activators fails, remove the interior upholstery panel from the corresponding car door (see chapter Body) and check the correctness of the voltage supply to the executive electromagnet by switching the control switch. One of the wires must be powered in one of the switch positions, the second in the other.
7. If power is good, replace solenoid.
8. If there is a power failure, check for an open and short circuit in the wiring in the section of the circuit between the electromagnet and the relay, as well as the condition of the relay itself.
Note. Most often, a wire break occurs in the area between the door and the body panel.