How to repair a door lock actuator

A power door lock actuator can be an integral part of a car door lock repair. If the remote device or the release switch fails, the drive may be defective.

Drives for car door locks are designed to lock and unlock the door without the effort of pulling the cable and rod.

In some vehicles, the door lock actuator is located under the latch. A rod connects the drive to the latch and another rod connects the latch to the handle sticking out from the top of the door.

When the actuator moves the latch up, it connects the outside door handle to the opening mechanism. When the latch is down, the outside door handle is disengaged from the mechanism so that it cannot be opened. This forces the outer handle to move without moving the latch, preventing the door from opening.

The power door lock actuator is a simple mechanical device. This system is quite small in size. A small electric motor turns a series of spur gears that serve as a gear reduction. The last gear drives a rack and pinion gear set that is connected to the actuator rod. The rack converts the rotational motion of the motor into the linear motion needed to move the lock.

There are a number of ways that you can unlock car doors that have door lock actuators, including:

• Key usage
• Pressing the unlock button inside the car
• Using the combination lock on the outside of the door
• Pulling the handle on the inside of the door
• Using the remote control keyless entry
• Signaling from the control center

There are two ways to determine if a drive is faulty:

• Using a remote device or keypad to unlock the door
• By pressing the unlock button on the door panel

If the door remains locked in either or both of these cases, the problem is with the actuator.

There are several reasons why a door lock actuator may need to be replaced. Sometimes the door lock actuator stops working completely. On some vehicles, the door lock actuator becomes noisy and makes a creaking or humming sound when the power door locks are locked or unlocked. If the motor or mechanism inside the door lock actuator wears out, the door lock may be slow to lock or unlock or work sometimes but not all the time. In some vehicles, a faulty door lock actuator may lock but not open, or vice versa. In most cases, the problem with the door lock actuator is limited to only one door.

In some vehicles, the cable connecting the door lock actuator to the inside door handle may be built into the actuator assembly. If this cable breaks and is not sold separately, the entire door lock actuator may need to be replaced.

Part 1 of 6: Checking the status of the door lock actuator

Step 1: Inspect the damaged door and lock. Locate a door with a damaged or broken door lock actuator. Visually inspect the door lock for external damage. Gently lift the door handle to see if there is a jammed mechanism inside the door.

This checks to see if the actuator is stuck in a position that makes the handle appear to be stuck.

Step 2: Open the damaged door. Enter the vehicle through a different door if the door you are operating from does not allow you to enter the vehicle. Open a door with a broken or damaged actuator from inside the vehicle.

Step 3: Eliminate the door lock. Try turning on the door lock switch to eliminate the idea that the door lock is not working. Then try to open the door from inside the car.

Whether the door is locked or not, the door must open from the inside by pressing the inside door handle.

• Attention: If you are working on the rear doors of a four-door sedan, be aware of the child safety locks. If the child lock is enabled, the door will not open when the inside handle is pressed.

Part 2 of 6: Preparing to Replace the Door Lock Actuator

Having all the necessary tools and materials, as well as preparing the car before starting work, will allow you to complete the job more efficiently.

Necessary materials

• 1000 grit sandpaper
• socket wrenches
• Phillips or Phillips screwdriver
• Electric cleaner
• flat screwdriver
• white spirit cleaner
• Pliers with needles
• New door lock actuator.
• nine volt battery
• Saving a nine-volt battery
• Ratchet with metric and standard sockets
• Razor blade
• Removal tool or removal tool
• small hammer
• Super glue
• Test leads
• Torque bit set
• Wheel chocks
• white lithium

Step 1: Place the car. Park your vehicle on a level, firm surface.

Step 2: Secure the car. Place wheel chocks around the tires. Engage the parking brake to block the wheels and prevent them from moving.

Step 3: Install a nine-volt battery. Insert the battery into the cigarette lighter. This will keep your computer up and running and maintain your car's current settings. However, if you don't have a nine-volt power-saving device, that's okay.

Step 4: Disconnect the battery. Open the hood of the car and find the battery. Disconnect the ground cable from the negative battery terminal by turning off power to the door lock actuator.

• AttentionA: If you have a hybrid vehicle, use the owner's manual only for instructions on disconnecting the small battery.

Part 3 of 6: Removing the Door Lock Actuator

Step 1: Remove the door panel. Start by removing the door panel from the damaged door. Carefully bend the panel away from the door around the entire perimeter. A flathead screwdriver or puller (preferred) will help here, but be careful not to damage the painted door around the panel.

Once all the clamps are loose, grab the top and bottom panel and pry it slightly away from the door. Lift the entire panel straight up to release it from the latch behind the door handle.

• AttentionA: If your car has electronic door locks, you need to remove the door lock panel from the door panel. Remove the screws securing the panel to the panel before removing the door panel. If the cluster cannot be disconnected, you can disconnect the wiring harness connectors under the door panel when you remove it. If the vehicle has special speakers that are installed on the outside of the door panel, they must be removed before removing the door panel.

Step 2: Remove the plastic film behind the panel.. Peel back the plastic cover behind the door panel. Do this carefully and you can reseal the plastic later.

• Functions: This plastic is needed to create a water barrier inside the door panel, as water always gets inside the door on rainy days or while washing the car. While you're at it, make sure the two drain holes at the bottom of the door are clean and clear of accumulated debris.

Step 3 Locate and remove clips and cables.. Look inside the door next to the doorknob and you will see two metal cables with yellow clips on them.

Pry up the clips. The top sticks up and out from the doorknob, while the bottom sticks up and towards itself. Then pull the cables out of the connectors.

Step 4: Remove the door lock actuator bolts and lock screws.. Locate the two 10mm bolts above and below the actuator and remove them. Then remove the three screws from the door lock.

Step 5: Disconnect the door lock actuator. Allow the actuator to lower, then disconnect the black electrical connector.

Step 6: Remove the lock and drive assembly and remove the plastic cover.. Pull out the lock and drive assembly along with the cables.

Peel off the white plastic cover that is held on with two screws, then separate the plastic door lock actuator that is held in place with two screws.

• Functions: Keep in mind how the white plastic cover attaches to the lock and drive unit so you can reassemble it properly later.

Part 4 of 6: Door Lock Actuator Repair

At this point, you will start working on the door lock actuator. The idea is to open the drive without damaging it. Since this is not a "serviceable part", the drive housing is molded at the factory. Here you will need a razor blade, a small hammer and a little patience.

Step 1: Use a razor blade to open the drive.. Start at the corner by cutting the seam with a razor.

• A warning: Be very careful not to get hurt by the sharp razor blade.

Place the drive on a hard surface and tap the blade with a hammer until it goes deep enough. Keep going around the drive to cut off as much of it as you can with the razor.

Carefully pry off the bottom near the pin body.

Step 2: Remove the motor from the drive.. Pry up on the gear and pull it out. Then pry the motor up from its plastic portion and pull it out. The motor is not soldered in, so there are no wires to worry about.

Remove the worm gear and its bearing from the plastic housing.

• Attention: Record how the bearing is installed in the housing. The bearing should return in the same way.

Step 3: Disassemble the engine. Using a sharp tool, pry off the metal tabs that hold the plastic backing in place. Then, very carefully, pull the plastic part out of the metal case, being careful not to damage the brushes.

Step 4: Clean and assemble the engine. Use an electrical cleaner to remove old grease that has accumulated on the brushes. Use 1000 grit sandpaper to clean the copper drum on the reel shaft.

Apply a small amount of white lithium to the copper parts and assemble the motor. This clears the electrical contacts for a proper connection.

Step 5: Check the engine. Place your test leads on the motor's contact points and connect the wires to a nine volt battery to test the motor's operation.

• A warning: Do not connect the motor to the battery for more than a few seconds as these motors are not designed for this.

Step 6: Reinstall motor and gears.. Place the pieces in the reverse order you took them off.

Apply superglue to the lid and reattach the lid and body. Hold them together until the glue sets.

Part 5 of 6: Reinstalling the Door Lock Actuator

Step 1: Replace the plastic cover and replace the assembly.. Attach the plastic door lock actuator back onto the assembly with two screws. Install the white plastic cover back onto the lock and actuator assembly by securing it with the two other screws you removed previously.

Place the lock and drive assembly with connected cables back into the door.

Step 2: Clean and reconnect the drive. Spray an electrical cleaner on the black electrical connector. After drying, reconnect the black electrical connector to the door lock actuator.

Step 3 Replace the bolts and screws of the door lock actuator.. Install the three screws back into the door lock to secure it to the door. Then install two 10mm bolts above and below the location of the door lock actuator to secure the actuator.

Step 4: Reattach Clips and Cables. Connect the metal cables near the doorknob by plugging the yellow clips back into the connectors.

Step 5. Replace the clear plastic film.. Replace the plastic cover behind the door panel and close it again.

Step 6: Replace the door panel. Place the door panel back on the door and reattach all the tabs by snapping them lightly into place.

• AttentionA: If your vehicle has electronic door locks, you will need to reinstall the door lock panel back into the door panel. After replacing the door panel, reinstall the cluster into the panel using the screws. Make sure the cluster is connected to the wiring harness. You may need to attach the connectors under the door panel before fully installing the panel in the door. If the car has special speakers that are installed on the outside of the door panel, they will also need to be reinstalled back to it after the panel is replaced.

Part 6 of 6: Reconnecting the Battery and Checking the Door Lock Actuator

Step 1: Replace the battery cable and remove the protective shield.. Open the car hood and reconnect the ground cable to the negative battery post. Tighten the battery clamp firmly to ensure a good connection.

Then disconnect the nine-volt battery from the cigarette lighter.

• AttentionA: If you didn't have a nine-volt power saver, you'll have to reset all your car's settings, such as radio, power seats, power mirrors, and so on.

Step 2. Check the repaired door lock actuator.. Pull on the outside door handle and check that the door opens from the locked position. Close the door and enter the car through another door. Pull the inside door handle and check that the door opens from the locked position. This ensures that the door will open when the door is unlocked.

While sitting in the vehicle with the doors closed, press the door lock actuator lock button. Then click on the inside door handle and open the door. If the door lock actuator is operating correctly, opening the inside door handle will disable the door lock actuator.

• AttentionA: If you are working on the rear doors of a four-door sedan, make sure you disable the child safety lock to properly test the repaired door lock actuator.

Standing outside the vehicle, close the door and lock it only with an electronic device. Press the outside door handle and make sure the door is locked. Unlock the door with the electronic device and press the outside door handle again. This time the door should open.

If your vehicle's door lock still does not work properly after repairing the door lock actuator, it could be further diagnosis of the door lock and actuator assembly or a possible electronic component failure. You can always go to a mechanic for a quick and detailed consultation from one of the certified technicians here at AvtoTachki.

It may be necessary to completely replace the drive. If you'd rather have a professional do the job, you can call one of our qualified mechanics to replace your door lock actuator.