Parking brake not working. Yellow warning on dash.

Varixto

Varixto

Member
And another headache...
This morning I went to the car and got the yellow parking brake warning on the dash. The light on the switch in the centre console is not lit. The parking brake is engaged so I can't drive the car. I plugged my OBD reader and got the following codes:
604A Parking brake servomotor left: Power supply
6581 Parking brake status unequal
Could anyone give me any pointers regarding what could be causing the issue? The parking brake module was replaced after having some water damage a few months ago... I have read online something about a software update for the module but I am not sure if this applies to my issue.
I am beginning to lose the love I had for the car, to be honest, and am considering fixing this and getting rid of it.
Any help or advice will be much appreciated.
 
Sadly it can be a s/w update needed... you could check to see of the left cable to the EPB is correctly seated..pull it out and refit and also try disconnecting the battery for say 15 mins and try..
 
As said check the wiring to the handbrake motors, as a temporary “fix” the handbrake can be wound back by connecting a 9 volt PP3 battery to the motor, depending on polarity it will either wind it on or off, you will have to do this to both side to enable you to move the car.
 
B21 said:
Sadly it can be a s/w update needed... you could check to see of the left cable to the EPB is correctly seated..pull it out and refit and also try disconnecting the battery for say 15 mins and try..
Click to expand...
I checked the left parking brake connector and everything seemed ok. So I gave your second suggestion a try (before this, I had tried with my OBD reader to clear the fault codes without success).

I reset the ECU by disconnecting the battery and waited 30+ mins. That seemed at first to do the trick.

When I reconnected the battery I saw the switch's light still off so I thought for a moment that the reset had not worked. However, when I pressed the parking brake button, I heard the parking brake being actuated (ie: disengaging the rear brakes). I pressed the switch again and the light came back on when engaging the parking brake. So it seemed fully operational again.
However, once I tried to start the car again, the same thing happened...so back to square one.
 
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Varixto said:
I checked the left parking brake connector and everything seemed ok. So I gave your second suggestion a try (before this, I had tried with my OBD reader to clear the fault codes without success).

I reset the ECU by disconnecting the battery and waited 30+ mins. That seemed at first to do the trick.

When I reconnected the battery I saw the switch's light still off so I thought for a moment that the reset had not worked. However, when I pressed the parking brake button, I heard the parking brake being actuated (ie: disengaging the rear brakes). I pressed the switch again and the light came back on when engaging the parking brake. So it seemed fully operational again.
However, once I tried to start the car again, the same thing happened...so back to square one.
Click to expand...
Sadly I suspect a firmware update required..folks running batteries below 50% charge shoot themselves in the foot..
 
I ran into a similar issue recently. Here’s what worked for me:
  1. Jack up the car and remove the rear left tire.
  2. Locate the parking brake actuator.
  3. Manually unwind the actuator so the parking brake loosens.
  4. I replaced the actuator, and it’s been working fine since.

For what it’s worth, I now only use the parking brake when I’m on an incline (which isn’t too common here in Chicago).
 
In the end it was the parking brake actuator on the passenger's side. It had stopped working so I had to replace it. The part from BMW was around £500!? I almost self-combusted when I found out.
Does anyone want a Z4? I'll pay you...
 
Varixto said:
In the end it was the parking brake actuator on the passenger's side. It had stopped working so I had to replace it. The part from BMW was around £500!? I almost self-combusted when I found out.
Does anyone want a Z4? I'll pay you...
Click to expand...
You can get a new non bmw part for around £50
 
B21 said:
You can get a new non bmw part for around £50
Click to expand...
Please don't rub salt into the wound...
I'm just kidding, thanks for letting me know. If the one on the other side packs up (which, knowing my luck, it will), I'll try to get an aftermarket one, following your advice. :):thumbsup:
 
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Varixto said:
In the end it was the parking brake actuator on the passenger's side. It had stopped working so I had to replace it. The part from BMW was around £500!? I almost self-combusted when I found out.
Does anyone want a Z4? I'll pay you...
Click to expand...
I paid £25 for mine from Amazon......
 
Varixto said:
Please don't rub salt into the wound...
I'm just kidding, thanks for letting me know. If the one on the other side packs up (which, knowing my luck, it will), I'll try to get an aftermarket one, following your advice. :):thumbsup:
Click to expand...
Autodoc usually offers a few options at different prices…
 
Going to say £25-30. Seems common part.
Couple of small bolts, about M4 or M5, i replaced with socket screws.
Line the round bit with grease before fitting as both of mine failed due water ingress and internal corrosion.
 

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flybobbie said:
Going to say £25-30. Seems common part.
Couple of small bolts, about M4 or M5, i replaced with socket screws.
Line the round bit with grease before fitting as both of mine failed due water ingress and internal corrosion.
Click to expand...
Did you wind both calipers back before changing or just remove the old one and bolt the new one on?
I am only changing one side and i am wondering if just putting a new one on one side will affect synchronisation of the handbrake pressure each side..
 
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