Park Brake Fail

[steve.pritchard146]

Hi all,
I have recently developed an parking brake fail and amber warning light on my 2008 X358 2.7d
I can't hear any motors if I activate the parking brake switch although if I push it down I get a chime and a red brake light on the dash comes on briefly in the dash.
Fortunately the brake is in the off position so I can drive the car - please can somebody point me in the right direction for fault tracing.
Thanks very much

Steve

[Andy P]

Hi Steve,
I'm afraid you have posted in the wrong section.(PERHAPS A MODERATOR CAN MOVE IT TO THE X350 SUB FORUM)
You need the X350 forum,here's the link to that Quite a lot of info on the electronic parking brake:
viewforum.php?f=285
Hope you get it sorted.
Take care.
Andy

[steve.pritchard146]

Doh! - Thanks Andy, I appear to be blind

[3.8etypephil]

Would you describe the symtoms in more detail, and any maintenance carried out immediately prior to the fault manifesting itself. What happens when you turn off the engine and remove the key? What happens if you attempt to set the brake manually, either when the engine is running, gearbox in "D"' for example at traffic lights? And if it sets, what occurs when you press the accelerator to pull away again? The more info, the better your chance of an accurate diagnosis.

[andypryce]

Do you have a code reader? Which amber light is on? Sounds like handbrake motor issue, but agree more investigation required.

[steve.pritchard146]

Hi Andy (sorry slow reply) I can’t remember the code, but I do have a reader and it’s a hall sensor failure.
I’ve actually bitten the bullet and got it booked in with Mike Allen in Swindon who seem to be reasonably respected. As they are dropping the rear subframe I’m getting them to do all the bushes.
I was going to do it myself, but with 3 other ‘project’ vehicles I decided I needed to keep at least one on the road

[PaulGover]

...it’s a hall sensor failure....

As far as I recall, when my handbrake failed, it was the same symptom. The cause was damaged wiring (a common fault, it passes through various grommets; there's also a splice in the loom to contend with) rather than the sensor - so the fix was not a new motor unit!

[steve_m]

A different car obviously, but all my parking brake problems vanished when I fitted a new battery.

[steve.pritchard146]

A different car obviously, but all my parking brake problems vanished when I fitted a new battery.

Well there is no doubt the cars are hugely sensitive to voltage drops however in this case my battery is brand new

[steve.pritchard146]

...it’s a hall sensor failure....

As far as I recall, when my handbrake failed, it was the same symptom. The cause was damaged wiring (a common fault, it passes through various grommets; there's also a splice in the loom to contend with) rather than the sensor - so the fix was not a new motor unit!

Yes, I was hoping for a wiring failure but have been categorically told not- they’ve also offered me the part due to be swapped so I was going to have a look inside…

[PaulGover]

What's annoying about this sort of failure is the bit that broke is merely there to check the rest of it worked; the actual motor probably still works. Given there are several ways to find out if the motor works - listen, watch and try the brakes, it's an unnecessary complication...

[steve.pritchard146]

Hi Paul,
Yes, the parking brake works fine as a recent MOT test revealed.

[steve.pritchard146]

As a follow and closure on this.
I have now had all rear suspension arms replaced and the parking brake actuator done at the same time - all is happiness and light apart from in the bank account department!