Mercedes X Klasse parking aid problem

Parking aid issues are a pain. Had something similar happen on my old BMW 3 series. Was the error message specific, pointing to a particular sensor or just a general parking aid fault? Did the diagnostics tool mention anything about the voltage readings for the ultrasonic sensors? Could be a faulty sensor, but you're right, it's often wiring. Have you checked the connections yourself, even just visually? Sometimes it's an obvious loose plug.

Thank you for your reply. The error message was indeed rather general, indicating a system fault instead of pointing to a particular sensor. I have visually inspected the connections I could easily access, but I did not check the voltage readings. Could you elaborate on where I might find the ultrasonic sensors and how to check their voltage?

Right, a general error makes it trickier. Checking voltage requires a multimeter and knowing the correct values, plus access to the wiring diagrams. The ultrasonic sensors are usually located in the bumpers, front and rear. Honestly, without the right tools and knowledge, you risk causing more problems. If you aren't comfortable with electrical testing, it's probably best to take it to a workshop. Did they confirm the faulty wiring with a proper diagnostic check?

Understood. Thank you for your assessment. I took your advice and brought the vehicle to a workshop. It turned out to be a corroded connector on one of the rear ultrasonic sensors, just as suspected. The connector was cleaned and the wiring repaired, resolving the issue. The final cost was indeed close to the initial estimate.