Citroen Berlingo - Error C1387 ABS: Decoding & Solutions for C3187 Wheel Speed Sensor Issue

Someone could decode the error C3187 wheel speed sensor (this is the description on the computer). The car had a rotten beam under the battery. The fight was long to fire it up at all, but somehow it worked. Now the customer brought the ABS and it started again, replacing the pump, rear ABS sensors because he was banging with errors. Now you can delete everything and the ABS works, but only about 2 km then lights up and error C1387. After switching off the ignition, it is there again, but only for 2 km. The speed of the wheels seems to see, but only for a moment then breaks the connection.

Hi!
Peugeot describes it: dormant wheel speed sensor consistency.
The description states that the speed difference found between the two wheels when driving straight ahead. Unfortunately, they do not specify which sensors it is about. It is a pity that you do not specify what model it is. Are the speeds of all wheels similar while driving? If it's a new Berlingo, is there a rotten beam from the rear sensors, the distance between the sensor plugs and the beam entering the floor, remove the conduit and pull the beam.
My guess is that the bundle rot is removed under the battery.

Damaged magnetic rings or tarnish.

Thanks, both of you were right. and your suggestions were absolutely correct.
But there was a new beam and new hubs on it and other rims on these hubs (not enough teeth) that was the cause of the fault, the front wheels were going 2X faster than the rear wheels and were banging with errors. The owner of the car misled me by saying that before the beam under the battery, everything was working ABS, of course, only now, that it supposedly worked then it did not work. It's hard to diagnose the computer because in Citroen, after exceeding 5 km, it breaks the connection with the ABS and you have to drive these 5 km and watch the speed. In any case, wearing the right laces did the trick. Two days of fighting but the car is done. Thanks again for your help

Hi!
In the original description of the error, there is also a discrepancy in the speed of the rear wheels as the cause, but you probably checked the size of the wheels, and I did not run into various sensors.