Mercedes Benz Parking Sensor Replacement

New Mercedes parking sensors cost $20 to $30 online, and the part of this job that goes wrong is the paint rather than the fitting. The sensor has to match your car’s paint code, for example 744 for the common silver or 040 for black. If the replacement arrives unpainted, scuff it with 500 grit before priming. Access is from behind the bumper, and some models need the bumper off.

What you will need

Many Mercedes models from the same era share the same bumper parking sensor, but not all of them do.

• Mercedes Parking Sensor

The same sensor is used on multiple models, including C S E CLK SLK CL M ML G GL R Class. Always verify compatibility with an auto parts seller or dealer.

Matching Color

New Mercedes parking sensors typically do not come painted. Therefore, the new sensor will not match the paint of your bumper and car.

Getting the new parking sensor to match the color of your car is easy. You will need to get a custom mixed spray can that matches the color of your Mercedes-Benz.

You need the paint color code of your Mercedes-Benz. Mercedes paint code can be found on the sticker on the driver’s door. It is on the right side of the label. It will end with three numbers. For example, 744, commonly silver, or 040 for black.

• Custom Mercedes Mixed Spray Paint

Procedure

Replacing the parking sensor on a Mercedes-Benz is very easy. This guide will show you how to replace a Mercedes parking sensor and paint the new sensor to match your car’s color.

1. Purchase/collect a new Mercedes parking sensor. It can be ‘used’ or ‘new.’ Make sure to match the part number. No coding will be needed.
2. Sand down the paint from the sensor. Scuff the surface with 500-grit sandpaper if the sensor is not painted.
3. Spray a light coat on the sensor and let it dry for at least fifteen minutes. Keep every coat thin: a thick build of paint or clear on the sensor face can weaken the ultrasonic signal and make the sensor misread. Apply a second coat of paint. If you are using single-stage paint, it will contain clear as well. But if you want the sensor to look as close to the original bumper, you can apply a coat of Automotive Clear Coat.
4. Determine the faulty or missing parking sensor. It’s hard to miss it.
   
5. You will need to access the sensor from under the bumper. In some cases, you may even need to remove the bumper.
6. Unclip or remove any bolts that hold the bumper in place. Mercedes-Benz uses plastic retainers and 10mm bolts, but Torx head bolts are used in some models.
7. Reach to the back of the bumper and remove the sensor by pressing the two locking tabs.
8. Press the new sensor into place and plug in the electrical connector.

Mercedes parking sensors can fail, causing part of the system not to work properly. Failure is due to an accident, or the sensor may stop working if water gets inside it.

You can also remove the sensor and try to dry it, but it doesn’t always work. Replacement sensors are straightforward to work with. New sensors can be bought online for $20 to $30.

If there’s a check engine light after replacing the sensor, use the YOUCANIC UCAN-II Pro to clear the stored codes. It can read and clear fault codes through every control module on supported vehicles.

Part Numbers

Common part numbers are listed below. Mercedes has superseded several of these over the years, so confirm the correct number for your car with the parts counter using your VIN.

• A2125420018
• 0045428718
• A0045428718
• 0263003556
• 0015427418

Symptoms of a Bad Parking Sensor

• A Parktronic or parking assist malfunction message on the dash
• Constant beeping with nothing behind the car
• No warning at all when you back up to an object
• The warning bars on the display stay red or flash

How to Find the Faulty Sensor

With the engine running and the car in reverse, the sensors work by sending out ultrasonic pulses. Put your ear close to each sensor, or lightly touch it with a fingertip; a working sensor makes a faint click or buzz, while a dead one stays silent. A scan tool such as the YOUCANIC UCAN-II Pro can read the parking system codes on supported models, which usually name the sensor position.

Before replacing a sensor, check for dirt, ice or a cracked sensor face, and look at the connector behind the bumper for corrosion. A bumper repair or a sensor that sits crooked in its holder can also trigger false warnings.

Which sensor, before you order one

These sensors look identical and fail one at a time, and the usual mistake is ordering a set because the system is down. The parking aid module records which sensor stopped reporting, so the car can tell you which one to buy if you ask it.

Asking requires a tool that reaches that module rather than the engine, and for a single repair rent one for seven days is the sensible route instead of buying. If the whole system is dead rather than one corner, check the fuse and power supply before assuming any sensor at all, because a dead system is more often supply than sensor.

Frequently Asked Questions

Can one bad sensor disable the whole Parktronic system?

Yes. On many Mercedes models a single failed or unplugged sensor makes the system switch off and show a malfunction message.

Do I need to paint the new parking sensor?

Most replacement sensors come in primer and should be painted to match. Use your paint code from the door jamb label and keep the coats thin so the sensor still works.

Is it safe to drive with the parking sensor warning?

Yes. The car drives normally, but you will not get a warning when parking, so check around the car carefully.

Check these troubleshooting and repair guides for more help on your Mercedes-Benz.

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