C4 electronic handbreak problems

[Paddynel0]

Hi everyone. Iv just joined this forum as a last resort. My 2010 c4 grand picasso electric handbreak has stopped working. (Not engaged) I recently had the rear break pads changed & since then the handbreak will not work. Iv had it to 3 different mechanics but no one can fix. Any ideas? Iv checked the button on dash and it's working fine. There is no noise to the handbreak module when button is pressed. I have attached a few pictures of the handbreak module.

[the2ems]

We’re the mechanics from Citroen garages?

[PaulC5]

I have read that the wiring to the back of these cars can break and also corrode internally so it needs to be checked from inside all the way to the rear calipers.

[Paul-R]

Who changed the brake pads?
Did they use the proper change procedure? This utilises a specific method using a high end code reader, preferably Diagbox, to put the callipers into the correct position for change over. Simply screwing the piston back can damage the calliper.

[RichardW]

I have read that the wiring to the back of these cars can break and also corrode internally so it needs to be checked from inside all the way to the rear calipers.

Not on a 2010 Paul - that only applies to the Mk 2 Versions from 2013/4 on. The Mk1 uses a central motor under the left front seat, with a common bowden cable to the centre of the rear axle, and then individual cables to each wheel. Pads on these can be changed without needing a computer. If there is no noise, then the motor is not running for some reason - really needs to go on a diag computer to find out why. Are there messages on the screen saying Hand break fault?

[Paul-R]

OK, same/similar to my X7. On that there is a procedure with Diagbox for resetting the system after new pads are fitted. Is there similar on the Mk1 C4? Could that be the cause of the problem?

(PS @RichardW you quoted the wrong Paul!)

[GiveMeABreak]

After they have been fitted, for the MK I Model with EPB, the official procedure states:

Using the diagnostic equipment:

• Carry out the electric parking brake calibration procedure
• Read and clear the fault codes using the diagnostic equipment
• Activate the electric handbrake control.
• Check the immobilisation of the wheels.
• Check the brake fluid level and top up if necessary.

As Richard says, it doesn't mention anything about putting the EPB into service mode on this model, but does mention the above afterwards. So it will need the correct diagnostic tool with the capabilities to do the calibration procedure (like Lexia / Diagbox). So unless they have damaged anything doing the job, and there is no electronic sound from the motor, it may have another issue. A diagnostic, again preferably with Lexia / Diagbox should determine what the problem is as long as there's communication with the ESP / and EPB ECU.