Citroen C5 X7 2.2 HDI - brake lights are on constantly when turning on the ignition

[iurimil]

Hello everyone,
I have a Citroen C5 X7 2.2 HDI, when changing tires I replaced the plastic bushings of the electric handbrake, I calibrated it then successfully and after two days an error message in ESP/ABS and the handbrake came on and when I tried to clean it with Diagbox they appeared again. I performed the procedure of deactivating, activating and calibrating the electric handbrake again, after which all errors in the individual modules related to were successfully deleted and have not appeared until now.
However, there is one problem that has been bothering me for several days and that is that the brake lights are constantly on when the ignition is turned on and are not affected by pressing the brake pedal. I checked the brake light switch on the brake pedal, but it is healthy. I replaced the brake light switch with a new one and there is no change. The brake lights are constantly on even when the brake light switch is disconnected from the connector. All fuses on the light line and the brake light switch are fine. I would like to ask you for some guidance on how to find the problem.

[admiral51]

Have you tried removing the brake light bulbs 1 by 1 and see if the other stays lit.
You could have a blown bulb that is shorting out.
Probably 100% wrong but a cheap and easy test

Colin

[iurimil]

Thank you very much Colin,
the problem turned out to be the sockets for the towbar's electrical network - they are located in the left trunk pocket. The sockets were in short-circuit mode. I don't have a towbar installed and both sockets were at the bottom of the left trunk pocket. However, the left trunk pocket had 5mm. - 6mm. of water which causes corrosion and a short circuit in the towbar sockets.
I was clear that there was a short circuit that duplicated the circuit of the brake light switch - I looked in detail at the diagram provided by Mark (GiveMeABreak) in several posts viewtopic.php?t=65527 , but I didn't know where to look.
So your suggestion Colin, made me open this area in order to dismantle each of the brake light bulbs. But with the opening of the left trunk pocket everything was clarified. I loosened and cleaned the bushings, raised them up, tied them up and everything is fine. I have properly working brake lights again!

[admiral51]

That is what i like, a nice cheap and easy fix.
Well done on finding it.

Colin