Single lock — general information and serviceability check (Honda Civic 6)

The device consists of control switches, door activators, a control unit and connecting electrical wiring. Diagnostics of lock failures is limited to checking the condition of the contact connections of the electrical circuit and the proper operation of the door activators. Since the system uses an electronic control unit, full diagnostics of its failures can only be performed using special equipment in a car service workshop. The control unit of the single lock is located under the instrument panel, to the right of the fuse box.

The operation of the single lock occurs due to the activation of bidirectional electromagnets located in the car doors. The control switch has two positions: LOCKED and OPEN. When activated, the switch sends a ground signal to the door lock control unit, which results in the corresponding switching of the activators. Depending on the initial position of the switch, when it is switched, the control unit simply changes the polarity of the current supplied to the electromagnets.

Some models may be equipped with an anti-theft system integrated into the vehicle's single lock. If the cause of the system failure cannot be found by performing the following checks, take the vehicle to a service station for a more complete diagnosis.

1. Always check the circuit protection status first. Remember that on some models the single lock circuit is protected by a combination of circuit breakers and fuses.

2. Switch the control switches in both directions with the engine off. Listen for the clicks that accompany the operation of the solenoids.

2. Switch the control switches in both directions…

3. Check the conductivity of the switches in both their positions (see accompanying illustration and table below). Defective switches must be replaced.

4. Check the conductivity of the electrical wiring in the section of the circuit between the switches, the control unit and the actuator solenoids. Repair damaged wiring.

5. Check the proper grounding of the switches and control unit.

5. Check the proper grounding of the switches and…

6. If only one of the actuators fails, remove the interior trim panel from the corresponding door (see Chapter Body) and check the correctness of the voltage supply to the actuator electromagnet by switching the control switch. One of the wires should be powered in one of the switch positions, the second in the other (see accompanying illustration).

7. If the voltage supply is correct, replace the solenoid.

8. If voltage is not supplied to the actuator, check the corresponding section of the circuit (between the activator and the control unit) for breaks and short circuits.

Note: Most often, damage to the electrical wiring occurs in the harness sections between the door and the car body and is a consequence of dynamic loads applied to the harness when opening and closing the door.