Solenoid for Brake Pressure (N247)

T

Thalion

Member
Hi,
For some times (years), I have had sometimes (once a month or more) a brake warning light at startup. But for the last few weeks, it happens way more often, and sometimes while engine is running after comming to a stop and moving again. I had mentionned this to a mechanic but they where unable to replicate the error and couldn't find anything.
It goes like this :
I turn on the car, the yellow warning light for brake and ESP turn on.
I drive a few metters and then a red warning is displayed on the MFD. with a warning sound, and stays until I switch off contact.
If I turn the contact back on, most of the time, now warning light, everything goes smoothly.
At all times, brakes work perfectly, ABS also.
VCDS scans give the following stored error (erasable) :
00814 - Solenoid for Brake Pressure (N247)
35-10 - - - Intermittent

I searched the ETKA to see where to find this solenoid, but haven't found anything.
Does anybody know if there's an easy fix ? Or a test to know what's wrong ?
Thanks
 
The Audi Workshop Manual has the following advice:

Audi Workshop Service and Repair Manuals > A2 > Running gear self-diagnosis for ESP, steering | Self diagnosis, V.A.G Inspection Service | Performing self-diagnosis | Checking of brake pressure solenoid valve, in brake servo -N247

A2 > Audi Workshop Service and Repair Manuals > Running gear self-diagnosis for ESP, steering | Self diagnosis, V.A.G Inspection Service | Performing self-diagnosis | Checking of brake pressure solenoid valve, in brake servo -N247
workshop-manuals.com

I believe the solenoid is built into the brake servo, and cannot be replaced on its own.
 
Hi,

do you have the MK20 ABS unit (will be listed in VCDS)?

If so, the solenoid is part of the brake servo. It in conjunction with a sensing micro switch are inside the brake servo and the solenoid pulls to provide the same force as pressing on the brake pedal to generate pressure to apply braking for the stability control.

There will be an electrical connector on the lower side of the face of the servo under the master cylinder. If the wiring is OK (you can check connectivity between this and the plug on the ABS unit) then the servo will need to be replaced. A new one is about £450 from Audi!

If you have a MK60 ABS unit then this won't be present. If this is the case then your ABS unit is probably faulty but this can be sent off for repair.

warm regards

Andrew
 
Last edited:
It is a 2001 1.4 petrol AUA, so I understand it should be the MK20 ABS unit (I will check this)
I will try the diagnosis and check the wiring, thanks for the tips.
I hope I won't have to change the servo...
 
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