How to replace the door lock relay

Electric door locks operate via a door lock relay located near the brake pedal, behind the stereo, behind the passenger airbag, or under the hood.

A relay is an electromagnetic switch controlled by a relatively small electrical current that can turn a much larger electrical current on or off. The heart of a relay is an electromagnet (a coil of wire that becomes a temporary magnet when electricity passes through it). You can think of a relay as some kind of electrical lever: turn it on with a small current, and it turns on ("levers") another device using a much larger current.

As the name suggests, many relays are extremely sensitive pieces of electronic equipment and produce only small electrical currents. But often we need them to work with larger devices that use high currents. Relays bridge this gap, allowing small currents to activate large ones. This means that relays can work either as switches (turning devices on and off) or as amplifiers (converting small currents to large ones).

As energy passes through the first circuit, it activates the electromagnet, creating a magnetic field that attracts the contact and activates the second circuit. When the power is removed, the spring returns the contact to its original position, again disconnecting the second circuit. The input circuit is off and no current flows through it until something (either a sensor or a switch closing) turns it on. The output circuit is also disabled.

The door lock relay can be located in four different locations on the vehicle, including:

• Under the dashboard on the wall near the brake pedal
• Under the dashboard in the middle of the cab behind the radio
• Under the dashboard behind the passenger airbag
• In the engine compartment on the firewall on the passenger side

This is a symptom of a door lock relay failure when you try to use the door lock switches on the door panel and the door locks do not work. Normally, the computer will block the relay circuit when using remote keyless entry, directing power through the alarm system, provided the vehicle is equipped with some kind of alarm. The key can still open doors manually.

Some computer codes that may be displayed for a faulty door lock relay include:

• B1300
• B1301
• B1309
• B1310
• B1311
• B1341
• B1392
• B1393
• B1394
• B1395
• B1396
• B1397

The following step-by-step guide will help you replace this part if it fails.

Part 1 of 3: Preparing to Replace the Door Lock Relay

Having all the necessary tools and materials in place before starting work will allow you to get the job done more efficiently.

Necessary materials

• Hex key set
• socket wrenches
• Phillips or Phillips screwdriver
• Disposable gloves
• Electric cleaner
• Flat head screwdriver
• needle nose pliers
• New door lock relay.
• Saving a nine-volt battery
• Ratchet with metric and standard sockets
• Torque bit set
• Wheel chocks

Step 1: Place the car. Park your vehicle on a level, firm surface. Make sure the transmission is in park mode.

Step 2: Secure the car. Place wheel chocks around the tires. Engage the parking brake to block the rear 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 running and save the current settings in the car. If you don't have a nine-volt battery, no big deal.

Step 4: Open the hood and disconnect the battery. Remove the negative terminal from the battery terminal. This will de-energize the door lock relay.

Part 2 of 3: Replacing the Door Lock Relay

For those under the dash near the brake pedal:

Step 1. Locate the door lock relay.. Approach the switch panel on the wall next to the brake pedal. Using the diagram, locate the door lock relay.

Step 2 Remove the old door lock relay.. Pull out the relay using needle nose pliers.

Step 3: Install a new door lock relay.. Take the new relay out of the package. Install the new relay in the slot where the old one sat.

For those located under the dashboard in the middle of the cab behind the radio:

Step 1. Locate the door lock relay.. Remove the panel covering the space under the stereo. Find the door lock relay next to the computer.

Step 2 Remove the old door lock relay.. Using a pair of needle nose pliers, pry out the old relay.

Step 3: Install a new door lock relay.. Take the new relay out of the package. Install it in the slot where the old one sat.

Step 4: Replace the panel. Replace the panel covering the space under the stereo.

For those located under the dashboard behind the passenger airbag:

Step 1: Remove the glove box. Remove the glove box so you can get to the screws holding the trim panel over the glove box in place.

Step 2: Remove the trim panel above the glove box.. Loosen the screws holding the panel in place and remove the panel.

• A warning: Be sure to disconnect the battery before removing the airbag, otherwise serious injury may result.

Step 3: Remove the passenger airbag. Remove the bolts and nuts holding the passenger airbag. Then lower the airbag and disconnect the harness. Remove the airbag from the dashboard.

Step 4. Locate the door lock relay.. Find the relay in the dashboard area you just opened.

Step 5 Remove the old door lock relay.. Using a pair of needle nose pliers, pry out the old relay.

Step 6: Install a new door lock relay.. Take the new relay out of the package. Install it in the slot where the old one sat.

Step 7: Replace the passenger airbag. Connect the harness to the airbag and secure the tongue. Reinstall the bolts and nuts to secure the airbag.

Step 8: Reinstall the trim panel. Place the trim panel back into the dash above the glove compartment and screw in any fasteners that were used to hold it in place.

Step 9: Replace the glove box. Install the glove box back into its compartment.

If you had to remove the air cylinders, be sure to set them back to the correct height setting.

For those located in the engine compartment on the fire wall on the passenger side:

Step 1. Locate the door lock relay.. Open the hood if it is not already open. Locate the relay next to a group of various relays and solenoids.

Step 2 Remove the old door lock relay.. Using a pair of needle nose pliers, pry out the old relay.

Step 3: Install a new door lock relay.. Take the new relay out of the package. Install it in the slot where the old one sat.

Part 3 of 3: Checking the New Door Lock Relay

Step 1 Connect the battery. Connect the negative battery cable to the negative terminal. This will energize the new door lock relay.

Now you can remove the nine-volt battery from the cigarette lighter.

Step 2: Turn on the door lock switches.. Find the door lock switches on the front doors and try the switches. If everything was done correctly, the locks should now work correctly.

If you still can't get the door locks to work after replacing the door lock relay, it could be further diagnosis of the door lock switch or a possible electrical problem with the door lock actuator. You can always ask a mechanic a question to get quick and detailed advice from one of AvtoTachki certified mechanics.

If the problem is indeed with the door lock relay, you can use the steps in this guide to simply replace the part yourself. However, if it is more convenient for you to have this work done by a professional, you can always contact AvtoTachki to have a certified specialist come and replace the door lock relay for you.