Parking Sensor Squealing Constantly on Corolla E12: Causes, Wire Issues & Troubleshooting Tips

Hello,
Corolla E12 with reversing sensors installed in the Dealership. The sensors were working properly until the rear bumper was removed. During disassembly of the bumper, one of the wires the sensors stopped off, it was a few-centimeter cable but not shielded, after mounting this sensor all the time as if it detects an obstruction, activates squeal even when there is nothing in the back of the car - or the reason may be the use of these few centimeters unshielded cable? How to check it carefully, when I eject one sensor from the circuit, the system will be as if it signaled an obstacle? because that's what happened to me when I had unplugged all - after turning on the backward one always crying at max.

Hello. I suggest to replace the entire sensor. Most likely it is damaged.

How to deactivate one sensor somehow? because the release itself will not solve the problem? Insert a resistance?

It is better to replace the defective sensor with a new one. Each parking sensor system has its own test mode, so you can check which sensor has failed. Replace it yourself or drive up to almost any mechanic who will do it often while you wait, and you will leave the workshop with an efficient system of parking sensors.

With the exchange just no problem I can do it alone, the only issue is to get such a sensor. Can it be any I find with the same dimensions or something different? Do you think that extending this sensor with a few centimeters of unscreened cable was not important for its faulty operation?

I have the same problem with sensors. Could you hint whether to replace the faulty sensor you need to pull the entire bumper, or just pull the sensor firmly? Thank you in advance.

You better take off the bumper. Because you can damage it.