Frustrating problem with my 2008, Jaguar XJ8

The stupid "parkbrake fault" light is on and won't go off. There's nothing wrong with the parking brake. I've even put the car in neutral on a steep hill and the parking brake works just fine.

Tried to get this fixed twice, not at a cheap place but at two different dealerships, once when the light first came on, and then again recently.

Dealership #1 said it was a computer problem. They fixed several other problems with the car, but after messing with it all day, they couldn't solve this problem. So I had to take the car back, as I was on a vacation and had to drive home.

So later, took it to Dealership #2, near my home. First they said the problem was the battery was too weak to get a good signal, as it was the original battery that came with the car, so it was 9 years old. I thought this was fishy, since if the battery was weak, shouldn't the battery light go on? But I let them replace it anyway, which of course, wasn't cheap. Well, guess what, I was pretty steamed to pick up my car and the stupid "parkbrake fault" was still showing. I had a heated discussion with the technicians who now said I needed to replace the parking brake. They said that even though it seems to work, the computer is sensing that its not working well enough. They want $1200 to fix it. I am not a rich guy, and that seems like a hell of a lot of money to replace a perfectly good parking brake, just to get rid of an error message! (not to mention, what if they are wrong again, and replacing the brake won't do it?)

This is the problem with overly computerized cars. On my 1999 Jag, I had a manual parking brake, and I could feel if it wasn't gripping well anymore. But with a push button parking brake I have to take the computer's word for it. Just to clarify, I can still drive the car, but that error message is constantly up, and if I cycle through the trip computer options it goes away for a few seconds then comes right back. Although the car will pass inspection, I think this would make it very difficult to sell.

Other than replacing the brake is there anything else I can try? Is there any hack or bypass to get rid of an incorrect error message? I would really like to drive and see the normal information in the display.

 

I've moved your post to the X350 tech section John, you should get a better response here.

 

They ought to have code(s) from the EPB's module. Each would be like C1234 or B1234. If you can get the code(s) people can maybe suggest what to do next.

If you would rather DIY the codes you'll need a suitable diag tool. Mongoose/Mangoose with IDS/SDD, WDS (if it supports your car), AutoEnginuity (hopefully reads EPB), or maybe the iCarsoft 930 (if it can read EPB).

Or I suppose you could guess (not great) and try some semi-obvious things (free up or replace the Bowden cables, clean or replace motor, ...).

 

Take the rear wheels off and manually apply/release the EPB. Don't be surprised if one caliper or the other is hanging up slightly.

 

I had similar issues. I unplugged the parking brake module in the trunk, cleaned the connectors with electronics spray, waited a few minutes, then plugged it back in. Never had those issues again.

 

The first place I would check is rear callipers,make sure both arms on the callipers where the cables connect to are sitting on the stop pins with handbrake off,then apply the handbrake and measure the distance traveled by each cable this will eliminate the calliper being faulty.

 

Have a read of this thread, it might help

https://www.jaguarforums.com/forum/x...-fault-115029/