Corsa Parking Aid Failure

Had a similar issue on my old Saab 9-3. Parking sensors went haywire. First thing to check is the wiring harness to the radar sensors, especially the plug connections. They're exposed to the elements and prone to corrosion. Also, inspect the control module itself; sometimes water ingress can cause havoc. Have you checked the fuses related to the parking aid system?

Cheers for the reply. Fuses are all good, I checked them first. Whereabouts are the radar sensors located on the Corsa? Are they easy enough to get to, or will I be wrestling with the bumper for hours?

On the Corsa, the ultrasonic sensors are usually mounted in the rear bumper. Accessing them usually requires removing the bumper, yes. Before you do that, trace the wiring harness back from the sensors as far as you can without disassembly. The fault is most likely within the bumper, though, but it's still worth checking. I suggest taking it to a shop and having them do a diagnostic.

Took it to the shop as suggested, and you were spot on! It was a corroded connector on one of the sensors. They cleaned it up and quoted me 95€ to fix it properly. Thanks for the pointers!