Do it yourself
Frequently asked questions about cars and motorcycles

How to Replace the Coolant Level Sensor on a Mercedes A-Class W169

Model: Mercedes Classe A W169 - Years: 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
Part: Engine coolant temperature sensor

See other generations:
Video tutorial

To replace the malfunctioning coolant level sensor on our Mercedes A-Class W169, first, drain the coolant into a container for proper disposal at an authorized disposal site. Locate the bright red coolant cap. Safely lift the vehicle; do not rely on your jack.

Release the air from the system and remove the hose, which is 0.4 in. Now, access the CTS from the hood by reaching the filter box. Here, you can see the coolant temperature sensor. Remove it with pliers by disengaging the clip that holds it in place.

Check with a voltmeter to confirm the sensor is indeed faulty. Now, install the new sensor, which can be tested with a phone app. Connect the sensor, refill the reservoir with coolant, and reposition the filter box. The job is complete.


Updated on 25 May 2026 by ScegliAuto


Related tutorials

Mercedes Classe A (2004-2012 / W169) In this video, see the procedure for removing and replacing the coolant temperature sensor on a Mercedes A-Class. First, open the hood and disconnect…
Mercedes Classe A (2004-2012 / W169) To check the coolant level in the reservoir of the Mercedes A-Class, lift the hood to access the engine compartment. The reservoir containing the coo…
Mercedes Classe A (2004-2012 / W169) Today, learn how to check the fluids of the Mercedes A-Class model W169. To perform the fluid check, open the hood. The first fluid to check is the e…

How to open the bonnet on a Volkswagen Golf?

In this tutorial, you will see how to open the bonnet on a Volkswagen Golf MK4. This is a very simple operation that follows the standard procedure. First, open the driver's door, then locate the lever in the lower left area and pull it. Next, move to the front of the vehicle, lift the bonnet slightly, and find the second lever located just above the Volkswagen logo. At this point, simply pull it towards you, fully open the bonnet, and secure it with the prop rod. To close it, gently push it down.

Watch the video!


by ScegliAuto

More videos