Skip the auto shop - Our mechanics make house calls

Q: Automatic door locking system issue

asked by on

My car has an automatic door locking system. Lately, it started malfunctioning. I had a fuse replaced and now it works but only intermittently. How can I fix this permanently?

A Mercedes of your model year use a combination electric/vacuum door lock system. The fuse was for the electrically powered vacuum pump only. The rest of system uses rubber vacuum lines which leak when old. You can replace them one at a time as they fail or leak, or all at once - a more expensive, but one-time repair. A YourMechanic professional can help diagnose the locks and repair this problem.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Dull knocking from the front end of the car noticeable at lower speeds

The noise would have to be heard to give a diagnosis for this. The noise may be coming from the brakes or suspension. The rack and pinion may be causing the issue but this would be difficult to determine without...

Q: Starting problems when the engine warms up

It's possible you have a leaking fuel injector - which is losing the residual fuel pressure in the fuel line. The fuel leaks into the cylinder, but leaves you with a partially filled fuel line. Diesel fuel injectors, when working...

Q: What could cause a clicking noise under the valve cover of my 1982 Mercury Grand Marquis

Hi there. Most of the time this is caused by a failure in one or more of the lifters in the engine. These are hydraulic and when they fail there ends up being too much clearance in the valve train...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...