Hi all,

Last week I changed the battery on my XK that had not been used in a while and battery died, so it now has a brand new battery.
Car started fine but had a "Park Brake fault message". The par brake is not on and no sign on dash of it being applied.
I did try the calibration routine (pressing foot brake twice and then applying park brake)... no result
I took my DTC reader and it says U0128 Lost Communication with Parking Brake Module.
Tried to clear the fault but it came back. Disconnected battery for 5mns, reconnected and same result... :-(
The car is not with park brake engaged as and it can move (didn't drive it but just reversed a bit on the driveway)
Any suggestions of things to try?
It need to go to service/MOT anyways but what is the impact of this message? Does it mean that the Park Brake can't be applied and that's it or other implications?

Many thanks

 

Does the parking brake actually operate when you pull up the handle? Obviously, if it doesn't work then it will be a fail. If it does work but the message still appears, then it might simply be an advisory but that might depend upon the attitude of the tester so you could ask before it is actually tested.

Richard

 

Sounds like you need to check & clean the connection onto the module. It's location depends on the model & if it's a convertible, it's detailed in the manual.

 

Is the 'brand new battery' FULLY charged - regardless of whether it was supplied as 'charged', did you put it on a charger overnight BEFORE fitting to the vehicle?

As I started reading your post, I did think this will resolve itself as you drive the vehicle. Unfortunately any warning light is now an MoT failure so you may not have this luxury of time available .......

Graham

 

"Does the parking brake actually operate when you pull up the handle?"
No, nothing happened.

 

I didn't check. Ordered from Halfords. The guy came and installed it straight away and didn't;'t test it (but I guess I could)

Edit: Just checked, it reads 14.2V

 

Yes I thought that might happen. Happened before with battery related issue resolved themselves as the vehicle was driven. So can the car be driven with a "Parking Brake" fault message?

 

Your 14.2 volt measurement is too high unless the car was running (but would indicate your alternator is charging the battery which is a good thing).

A lead acid battery, with the car off, should measure 12.6 volts or slightly higher when fully charged. I would follow Graham’s advice and fully charge the battery, with a substantial (10 amp or more) battery charger, just to make sure it is topped up. Check the voltage at the battery terminals with an actual volt meter if you can.

Disconnect both the + and - battery cables from the battery and touch the cables together (a hard reset). This discharges any stray voltages lingering in the car electrical system and modules.
Securely reconnect the terminals to the battery and follow the parking brake reset instructions displayed in the message area of the dash which I recall says depress and hold the brake pedal down (only once I think) and pull up on the parking brake lever in the center console. You may also have to reset the power windows after the hard reset as well.

All the above items are cheap and quick to perform to get your problem resolved. Good luck and let the forum know how you make out.

 

I have to give the responsible answer.

It is DRIVEABLE with the park brake stuck OFF but not legally on UK public roads with a known brake fault.

Graham

 

I've been getting the same issue on my x351 XJ. Same code. Parking brake is operational.

 

Thanks Graham.
Its next journey will be to the service and MOT next week anyways so that ok. Just want to make sure it won't cause damage to drive it there.

 

Hi all,

I thought I'd post a quick update. Car has gone to garage today.
Unfortunately they have not been able to diagnostic the problem as yet... I understand they are awaiting feedback from the diagnostic company (??? don't know if its Jag or third party) based on error codes presumably.
So I am waiting anxiously as to what the problem might be (... and the corresponding fix invoice... )

 

Right, another update: It seems the module is dead... :-( So new module needed (seems to be around 300 new when available!!!)
From what I could Google, for a 2006 Reg (2007 model I believe), the ref is 6W83-2C496-AD. Can someone confirm the actual part number?
They don't seem to come by so frequently... Even new part suppliers don't seem to have them in stock.
There are plenty on eBay of the 2009-2013 variant (6W83-2C496-AB I believe) but not earlier variant... any thoughts?
Thanks

 

Wouldnt the -AB be earlier than a -AD?

 

Adding… despite what anyone else says, I’ll bet a pint its your battery.
If I lose, As luck should have I’m in the UK often…andI really enjoy having a pint with others.

 

I would think so but garage confirmed the part is 6W83-2C496-AD...

£487 from Jag..., ouch!

 

Well I don't know. Battery is brand new. It is a "Yuasa HSB019" but oddly when I measured it, it said 14V???
Wondering is the higher voltage could have somehow cause the damage in Park Brake module???

 

with the car running youll measure 13.8 to 14.5v.

If you measure the battery right after turning the car off it will still be somewhere up by 13.8 to 14.5V.

Turn the car off and let it sit overnight and then measure the battery before you start it the next day and see what it measures. it should be around 12.6 v or higher.

 

Wish people would put resolution history in threads

I got same issue
And screen that wont come on

After a 50 mile run the new battery rests at 12.3 volts

Im changing the battery under warranty (and yes i also fully charged it)

 

Me too.
And as I’m sure you are aware, 12.3v is the reading of a battery at less than 50% of capacity. And that is not enough.
Cheers!