Mercedes-Benz ML400 Car Door Lock Relay Replacement at your home or office.

Our mobile mechanics offer services 7 days a week. Upfront and transparent pricing.

Estimate price near me

Service Location

Customer Ratings

(5,558)

Included for free with this service

Online Booking

Mechanic comes to you

12-month / 12k-mile warranty

Free 50 point safety inspection

Our certified mobile mechanics can come to your home or office 7 days a week between 7 AM and 9 PM.

Customer Ratings

(5,558)

Car Door Lock Relay Replacement Service

How much does a Car Door Lock Relay Replacement cost?

On average, the cost for a Mercedes-Benz ML400 Car Door Lock Relay Replacement is $135 with $40 for parts and $95 for labor. Prices may vary depending on your location.

CarServiceEstimateShop/Dealer Price
2015 Mercedes-Benz ML400V6-3.0L TurboService typeCar Door Lock Relay ReplacementEstimate$195.63Shop/Dealer Price$233.29 - $306.90
Show example Mercedes-Benz ML400 Car Door Lock Relay Replacement prices

What is the Door Lock Relay all about?

Power door locks used to be a luxury feature on vehicles, but they've become so mainstream that nearly every vehicle is now equipped with them. The lock’s function is to make securing your vehicle, as well as passengers, simple and easy. Instead of reaching across the vehicle to lock or unlock the doors, it can be done by simply pressing a button. Pressing the button completes a circuit, enabling the lock actuator to receive power which activates the locking mechanism to the desired position. The circuit is routed through a door lock relay, which acts as a switch to direct the power to actuators on the door locks. When unlock is pressed, the door lock relay switches from a neutral position to activating a pulse of power to the unlock circuits on the actuators. When the lock button is pressed, a pulse of power is switched to the lock circuit of the actuator to lock the doors. When the relay for the door locks is not working properly or sticking, either the lock function, the unlock function, or both are inoperative.

Keep in mind:

  • When service is performed on any electrical system, the battery should be disconnected to prevent accidental damage or injury.
  • If the door lock relay needs to be replaced, it can be indicative of an underlying concern with the power door locks.
  • Some vehicles equipped with remote keyless entry will find the key fob operates the driver’s door lock even while the door lock relay is defective.

How it's done:

  • Test the operation of electric door locks.
  • Test the fuse for that circuit.
  • Test the relay.
  • Replace the faulty relay.
  • Test for proper operation of electric door locks.

Our recommendation:

If you are experiencing problems with your power door locks, have one of our expert technicians diagnose and repair the system. Relays and electrical systems can be complex, and a broken wire or door lock actuator problem can easily mimic the symptoms of a door lock relay and vice versa.

What common symptoms indicate you may need to replace the Door Lock Relay?

  • Power door locks don’t lock when you press the button, while the unlock feature works.
  • Neither the lock nor unlock functions work.

How important is this service?

Power door locks are a convenience feature on your vehicle. If the power locks aren’t working, you can use the key to unlock your door and the locks can be manually operated as well. Have the power door lock system repaired at your convenience.

Fast and easy service at your home or office

Backed by 12-month, 12.000-mile guarantee


Meet some of our expert Mercedes-Benz mechanics

Real customer reviews from Mercedes-Benz owners like you.

Excellent Rating

(5,558)

Rating Summary
5,170
189
54
28
117
5,170
189
54
28
117

AJ

9 years of experience
21 reviews
AJ
9 years of experience
Mercedes-Benz C280 L6-2.8L - Tune-up - Bothell, Washington
Got here right on time. called ahead to coordinate the work, worked quick and kept me informed. Was able to see the parts removed and talk about the car's condition. Did a great job for me on a Mercedes.

Kevo

312 years of experience
189 reviews
Kevo
312 years of experience
Mercedes-Benz S320 L6-3.2L - Automatic Transmission Fluid Service - Sacramento, California
Kevin DID A FANTASTIC JOB on both our cars!! He explained everything very well and gave some great pointers on making our cars run better and longer!!

Ricardo

14 years of experience
339 reviews
Ricardo
14 years of experience
Mercedes-Benz ML350 V6-3.5L - Spark Plugs - Torrance, California
Hi is very kind and did all he could to fix the problem. He stated that he did not have the equipment and that I should bring it into the dealership. I appreciate the convenience provided by your company and the courtesy and professionalism of Recardo and your company.

Jesus

16 years of experience
68 reviews
Jesus
16 years of experience
Mercedes-Benz C240 V6-2.6L - Reset Indicator Lights - Riverside, California

Excellent Rating

(5,558)

Rating Summary
5,170
189
54
28
117
5,170
189
54
28
117
Number of Mercedes-Benz services completed
61138+
services done by our mechanics
TOTAL NUMBER OF EXPERT Mercedes-Benz MECHANICS
1100+
experts on our platform

Recent articles & questions

The Best Used Cars to Buy If You Live in a Tropical Climate
If If you live in a tropical climate, most of your vehicle purchasing concerns will be essentially the same as if you lived anywhere else – you want a car that looks good, offers decent gas mileage, and suits the...
Symptoms of a Bad or Failing Accelerator Cable
Common signs include damage to the outer covering, delayed accelerator response time, and problems with cruise control.
How to Replace a Door Lock Cylinder
A cylinder lock ensures the proper function of your door locks, which help protect against car theft. Replacing this part takes time and know-how.

I can't locate the headlight relay for my 1992 Oldsmobile Bravada 4.3L type W.

Hi there. Check under the dashboard around the mounting surface for the steering column and you will see a fuse box. In that fuse box you will find the flasher and a relay. The relay is for the high and...

Does a 2006 jeep grand cherokee 3.7 need a fan clutch ?

The fan clutch was only used on the 4.7L engine. It will not be present on your engine (the 3.7L) and so you will only have the radiator shroud and fan assembly. If you are having any issues with the...

Does the Chrysler 4.0 V6 have a timing belt that must be changed?

Hi Stephen. Thanks for contacting us tonight. The 4.0-liter V6 engine has a timing belt that needs to be changed every 100,000 miles.

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com