Intermittent Park Brake failure (yellow Light)

[99ron]

Getting intermittent Park Brake Failure error flagged on the 3.0SD - Yellow Park light on for a few seconds and then it clears. Then happens again a few minutes later. The park brake works when the error isn't active. I've got a 1000 mile drive home from Italy on Friday and it is going to drive me crazy "bonging" every few minutes. Any ideas what this could be caused by?

[99ron]

Have pulled the park brake fuse to create a permanent error until I get back home. I lose hill hold but I am blessed with two feet so can deal with that. Just had to stop that bonging every few minutes. It drives you insane. There should be an idrive function to mute the noise.

[99ron]

Well home safely from Italy last week (French route on way home much nicer than Belgium/Germany/Austria route I took to get there... smooth French autoroutes less bumpy for the X5! and despite hitting 130MPH in Germany was much quicker!).

Anyhow not sure what I've done to fix this but passing on info in case it helps anyone else in the future.

I hooked up some INPA diags from the laptop and thought I'd connect the battery charger whilst playing as these cars seem to like to drain the battery quickly with all the elecs running. Unfortunately the cable I got from Fleabay is no good (K not DCAN) so ordered another. In the meantime I put the fuse back in to clear the perm park brake error. The fault cleared and two days later has not made another appearance.

I will keep an eye and hopefully next time will have some diag codes if it does happen again. I did read somewhere that if the battery charge gets low then the park brake is typically the first item to throw wobblies but not sure how true that is. I did have aircon/cooled seats/headlights/wipers/music and god knows what else on during a storm in high heat so the battery was under some load, although it kept bonging every few minutes for a couple of days -  until I eventually pulled the fuse to shut the constant alarms up.

[kenniff]

This may not be your problem, but when I had an E70 if had a similar issue with the parking brake failure (intermittent). On taking it to the dealer they said it was a "known issue" and fixed it under warranty.

[AVI-8]

Possibly a dodgy switch/sensor on the handbrake lever?

[99ron]

Hmm... battery just died on the missus whilst in town. RAC jumped started but declared the battery knackered.. maybe those park brake alarms were an early warning to battery failure.