Marcin Z

Just to add as a clarification, the wire needs to be cut when the lock is disengaged. Otherwise it will remain permanently engaged. I realise that this solution may not be for everyone, but for me the age of my car and relatively low value of it would be enough to justify such a crude "repair".

Wasn't there a fix where you just had to cut one wire and that would disengage the lock? I think I've seen a YouTube video to that effect. Apparently the mechanism can be problematic as cars get older. Could be mistaken and I'm sure someone wiser will correct me here. Of course the procedure would mean the lock is permanently disabled, no matter if the key is in the ignition or not. My car has a steering lock permanently disabled. Done by the previous owner (I guess he had some issues with it). The fact that it has been "disconnected" has not caused any issues during my ownership of the car.

I've accessed the wiring harness in the boot area. I've stripped a very short section of the two wires that supply power to the parking brake motor. My car is an SE model and there are only four wires in that part of the harness (two for parking brake and two for abs sensor I guess? not sure if the esp and abs is the same sensor?). I have bypassed the harness from that point and used a length of spare wire to connect the parking brake motor through an open boot lid. The parking brake engaged and disengaged as it should. I am assuming that the harness is faulty somewhere between the point where it enters the boot and where it connects to the electric motor. I was going to fashion a more permanent bypass, but found a cheap replacement harness (not OEM) and am tempted to get it and replace the whole thing. It does not look too difficult and I already have access to it from the inside, so just need to remove the wheel arch i think and then it should be fairly simple. One thing I will add is that even with the bypass and parking brake working, the fault on the dashboard remained. I don't know if you need to delete the fault code or should it disappear automatically once everything is working correctly? I don't have a code reader so will need to ask the garage.

Checked the fuses. They are ok. I suppose it could be a relay, but I've done some reading that seems to suggest a corrosion in the parking brake harness is not uncommon. Though the only way to check would be to cut the harness open. I think you can buy a replacement plug (the end that connects to the motor housing) with 30cm of wire or so attached to it and then do some surgery on the harness. Maybe that is the answer. In the meantime there is the red flashing parking brake warning on the dash at all times. Foot brake operates as normal (and works on the affected wheel too; I've checked with the wheel in the air). I left the left parking brake disconnected. The one on the right still works fine.

Thanks for the suggestion Steve, but I've checked the pins and the movement and all is as it should be. However, I have also plugged the motor back in, but without attaching it to the caliper and got another person to activate the handbrake while I was under the car. The motor did not activate. The one on the other side did. I then attached a voltage meter to the plug and again had another person activate the handbrake. The meter shown no voltage coming through. I assume in that one or so second when the handbrake is being activated there should be 12 volts coming through the plug. Similarly, no current was registered when the parking brake was being deactivated. So I am inclined to think the problem is with the wiring. The wire from the motor goes up somewhere, but I'm not sure what it connects to further up. Any suggestions would be helpful. Also, is there by any chance a separate fuse for the left and for the right parking brake?

Thank you for your replies and suggestions. I took the motor housing off the caliper. The caliper/piston works fine and nothing is seized in that part of the system. I then plugged the motor to 12v output and it spins. So the mystery deepens. I will try to connect the motor to the plug and see if it activated when I press the parking brake button, but this will have to wait as I have run out of time now. How loud should the electric motor be? When I connected it to 12v it was spinning (both ways), but sounding quite loud. Not overly loud, maybe like a drill on a very low speed. Difficult to explain in words I guess.

When you say brake linkage do you mean the mechanical parts inside the motor housing?

Hello, I'm just after a bit of advice regarding replacing the electric motor part of the rear caliper which operates the parking brake. The brakes work fine when driving, but the parking brake on one side (left) is inoperable and does not engage (and last time it did it struggled to disengage, which I resolved by repeatedly engaging and disengaging parking brake until it actually worked; haven't used the parking brake since). I suspect the electric motor is seized. If I wanted to replace it, is it as easy as taking out two screws, unplugging the wire, and then simply attaching the new electric motor and plugging it in? I do not intend to replace discs or pads as part of this process.

I have a pre-facelift (2005) A6 and it has a key slot in the boot lid near the rear registration lamp. You cannot see it unless you crouch down and look from underneath. Is that not an option on the facelifted cars?

I would stick to the standard ones. Do you know if "drilled and grooved" brakes you were looking at actually offer any improved performance? It would be interesting to know. However, I have never been in a situation where I thought that standard brakes were not enough. I would just save my the money and buy regular brakes. Just my view.

Unless I am missing something surely connecting the jump leads would at least illuminate the dash with ignition switched on, even if it did not manage to start the engine. I think maybe this is a bit more than a battery issue. Just my thoughts.

Would it make sense to try and start it with jump leads? If it starts then you know starter is ok, and maybe the issue lies with the battery. In any case you will probably need to do this if you are planning to take it to a garage to get the battery tested.

At the risk of stating the obvious, but could it be possible that the replacement screen is faulty? Especially if it is a second hand one? I know this does not happen very often, but maybe it is as simple as that. I have once bought a reconditioned part and it was faulty (although it was then replaced by the shop without any hassle). I'm sure it has happen to others as well. Other option could be the faulty screen on/off button perhaps? Not much help, I know.

Thank you for your replies and suggestions. In the end a lot more persistence and a different flexible wire has sorted out the issue.

I don't have anything to suck it with. I think I'll just keep trying to push the wire through from the top and see how it goes. I was also thinking if I could try and blow some compressed air through it, but not sure if this could cause any damage or not.