Parking Brake Failure

[afropelican]

Happy Holidays All!
Looking for some advice on potential solutions to the following faults:

Background:
Last month (25th Nov) my X5 after starting the car said parking brake partially available on the dash and parking brake not fully effective on the i drive.

However, It would actuate as normal and auto hold would function as normal.
Even activating mechanical brake and leaving in neutral with the ignition off, the car would not move.

The fault code were, 480524 Parking button function lighting, 480A0D emf speed detection faulty, 480540 Internal Control Unit General short circuit Error.

Resolution:
The fault disappeared itself after a few days so I never took it in to the garage.
As preventitive measures in november:
I fully charged the car (Battery was replaced last year so unlikely to be the issue).
I also replaced the parking button being the cheapest part to replace.

There was no issues since and car worked as normal for the next few weeks,




24/12/2022
While driving along at motorway (highway speeds)
The parking brake light started flashing and I got Parking Break Failure and Automatic Hold not available on the dash.
I can not apply the brake and the parking brake light remains yellow unless I try to apply the parking brake in which case nothing happens mechanically and the red parking light flashes on the dash with a warning saying parking brake failure.

The fault codes are 480502 Button Line 1 interruption, 48052A Button Function Pulling Defective, 480524 Button Function lighting short circuit supply,

I suspect the parking actuator has failed, but before I purchase this does anybody have any experience with similar faults and what the solution was for you?
Is there any further diagnosis I should be doing?
Is there a separate parking brake control module or is this built into the actuator?

A genuine parking brake modules is quite expensive (£1000) does anybody have any experience with the aftermarket generic modules as these only cost £250?

Being the festive period it will be a while until I can get to a garage, how much can the park function on the gearbox hold or should I avoid parking on hills in the meantime?

Thanks in advance.

[afropelican]

I also now get cruise control failure message in the I-Drive - could this be realated to the parking brake failure?

[RED_Y_]

Why do you suspect the actuator if most of the errors pointing to the parking brake button?

[afropelican]

Hi RED_Y_,

Reason why I don't think its the button is:

I replaced the parking brake button in November with a new one.
The scan tool I have which displays button position and it changes state as I pull the button / press the auto hold button.

I also tried putting back the old button yesterday and the same fault exists.


On a side note,
I also pulled the connector at the parking brake module and cleaned with contact cleaner - there was no sign of corrosion on the terminals but just in case.
To address the "EMF Speed Detection Faulty" I monitored the speed on each ABS sensor when the car was driven at various speeds and they where all reporting similar figures.

[andrei13]

Hello. Recently I got the Parking brake failed error too on my F15 40D 2015. I scanned for error and got the following : 480517 / 48052B / 48051A.

And I also get cruise control failure message.

Can you tell if you repaired your car and what the problem was?

[afropelican]

Hi Andrei13,

Unfortunately I've not had any luck with repairing it.
Going to be booked into garage soon as I've spent too much time working on it!!

Have you had any luck with getting yours repaired?

As an update to my diagnostic:
1. I have tried replacing parking brake button with a new aftermarket, and a used OEM button and still get the same faults.
2. I have inspected the loom from parking brake actuator until it enters the body and from the parking brake switch until it disappears below the gearstick and see no defects.
3. I have replaced the parking brake actuator with a used actuator (not tried new as I would prefer for a garage to do this as its an expensive part!) and I still get the same fault codes.

1. Does any body have any suggestions?
2. Does any body know where the grounds are for this portion of the circuit?
3. Which module does the parking brake circuit connect to?
(And ideally where is this located in the vehicle so I can check connections there)
4. Does anybody have a scan tool and can record line voltages when the button is at rest, pulled and pushed?

Thanks.

[danii]

Hello. I am facing the same issue and would appreciate any help before heading to the mechanic.

1. 48051A Actuating Unit: Emergency Release
2. 48052C Actuating Unit: Cable Crack

Plus cruise control failure, possibly related to EMF.

[EBD]

Check if EMF parking brake contol unit in the trunk is not flooded.

[danasn]

I get the same messages. But only when its warm or hot outside. not in the winter months.

I'm suspecting wheel speed sensor (s). But haven't narrowed it down yet.

[Erkif15]

Hello gents,

Did somebody get some results on this parking brake + adaptive cruise controll error situation?

I have the same issue, from time to time i get the parking brake error and also adaptive cruise control error, shut off the car and turn it on again and sometimes the problems are gone, cruise control working and also parking brake and auto hold.....

I did charge the main battery through the terminals under the hood, did not help, i have heard that you should charge the smaller battery separately? disconnect it from the harness and connect charger direct ?

Erki

[Erkif15]

I managed to fix the issue, the power socket to the parking brake box was 1mm loose, thats it, now works like a charm. Defenetly worth to wiggle all the connections before goin to service

[rtreyna]

Originally Posted by afropelican

Hi Andrei13,

Unfortunately I've not had any luck with repairing it.
Going to be booked into garage soon as I've spent too much time working on it!!

Have you had any luck with getting yours repaired?

As an update to my diagnostic:
1. I have tried replacing parking brake button with a new aftermarket, and a used OEM button and still get the same faults.
2. I have inspected the loom from parking brake actuator until it enters the body and from the parking brake switch until it disappears below the gearstick and see no defects.
3. I have replaced the parking brake actuator with a used actuator (not tried new as I would prefer for a garage to do this as its an expensive part!) and I still get the same fault codes.

1. Does any body have any suggestions?
2. Does any body know where the grounds are for this portion of the circuit?
3. Which module does the parking brake circuit connect to?
(And ideally where is this located in the vehicle so I can check connections there)
4. Does anybody have a scan tool and can record line voltages when the button is at rest, pulled and pushed?

Thanks.

Did you resolve the issue? I am having the exact same problem.

[avdg]

Hello,

I tot identity the Same Problem, I changed the actuator bot the problem persists ... does anyone had a fix for the Problem?

[afropelican]

Hi All,

Happy New Year.

Just an update - I ended up taking the car to a specialist BMW mechanic early 2023.

After a thorough diagnostic / test plan:
Discovered high resistance on the wiring loom by back probing / depinning the connector.
Fault traced to a wiring break behind the RR wheel arch.
After repairing the wiring, and rerouting to avoid rubbing in future, the fault was resolved.
Original Parking Brake Module, this did not require changing.

This was over 6 months ago and the fault has not returned with cruise control working perfectly. I wanted to be absolutely sure this did not return before updating the thread.