2. The electric door lock drive is activated by reversible solenoids located in the doors. The lock switches have two operating positions: locking and unlocking. When activated, the switch sends a ground signal to the door lock control unit to lock or unlock the doors. Depending on the method of activating the switch, the control unit completely changes the polarity of the solenoids, allowing them to be used alternately as the power side (positive) and the grounding sides are two sides of the electrical circuit.
3. Some vehicles may have an anti-theft function built into the power door locks. If you are unable to locate the problem using the following general points, contact your dealer's service department or other service station that is properly equipped.
4. Be sure to check the electrical circuit protection first. Some vehicles use a combination of switches and fuses.
5. Operate the door lock switches in both directions (locking and unlocking) with the engine off. Listen for clicks when the electromagnets operate
6. Check the switches for electrical continuity. Remove the switches and take them to your dealer's service department or other qualified service station for inspection.
7. Check the electrical wiring between the switches, the control unit and the electromagnets for integrity of the electrical circuit. Repair the electrical wiring if there is no integrity of the electrical circuit.
8. Check the condition of the grounding of the switches or control unit.
9. If all but one locking solenoid are working, remove the trim panel from the door in question (see chapter 11) and check for voltage in the solenoid when the lock switch is activated. One of the wires should be energized in the lock position; the other one must be energized in the unlocked position.
10. If the inoperative solenoid receives voltage, replace it.
11. If the inoperative solenoid does not receive voltage, check the relay for an open or short circuit in the wire between the locking solenoid and the control unit.
The original publication can be found on the website TOYOTAMAN.ru
Note: A typical failure is a break in the wiring harness between the body and the door, because opening and closing the door leads to fatigue wear of the wires and, ultimately, to their breakage.