A3 8V 2014 S line 1.8TFSI Electronic Parking Brake Fault

Help please, all suggestions welcome.

Some 2 years ago it started, just an occasional yellow parking brake symbol. The car would drive normally.

Reading that a failing battery can be the cause, I had a new genuine Audi one fitted. Re-occurred. Local garage said right rear caliper error reported.

New, pattern-part caliper fitted. Week or so later re-occurred.

Taken to main-dealer, 4 times, for investigation. Suspected, but not proved, ABS ECU suggested.

Had local garage send the ECU for testing for suspected intermittent fault. No fault found, so refitted. OK for a couple of weeks then re-occurred.

Took care to different dealer, changed the wiring-loom to right rear caliper as suggested by ECU tester. No change, garage suggested pattern-part caliper the cause so genuine Audi one fitted.

OK for 6 weeks then re-occurred.

Had parking brake switch changed, no change.

The fault never goes away by itself, when it is there, yellow flashing brake symbol and brake switch light flashing. Operating the switch most times does nothing and no noise from the brake motors. If start and drive, loud audible intermittent alarm, alternating yellow brake icon with red triangle icon and message "Parking brake is applied" and parking brake switch light flashing.

Just occasionally operating the switch clears the fault and the motors can be heard working.

I now am in the habit of never applying the brake (automatic so car won't move). But most times now, despite leaving the car without the brake applied, next time I use the car the yellow symbol, flashing brake switch light come before even starting the engine.

Thankfully only twice have I found the brake actually applied and won't release. Some time later have been able to release it.

I have tried a reset found on the web of applying the switch down for 7 seconds then up for 7 etc. Also tried battery disconnect.

I have attached a full VCDS scan.

After a battery, 2 caliper-assemblies and wiring-loom and over £3k, no further forward. An ECU would be over £2k.

Help please, the alarm blaring away in the car is driving me mad.

Love the car but.....

Audi-A3-8V-Jul2026.txt

39 minutes ago, Jono78 said:

A3 8V 2014 S line 1.8TFSI Electronic Parking Brake Fault

Help please, all suggestions welcome.

Some 2 years ago it started, just an occasional yellow parking brake symbol. The car would drive normally.

Reading that a failing battery can be the cause, I had a new genuine Audi one fitted. Re-occurred. Local garage said right rear caliper error reported.

New, pattern-part caliper fitted. Week or so later re-occurred.

Taken to main-dealer, 4 times, for investigation. Suspected, but not proved, ABS ECU suggested.

Had local garage send the ECU for testing for suspected intermittent fault. No fault found, so refitted. OK for a couple of weeks then re-occurred.

Took care to different dealer, changed the wiring-loom to right rear caliper as suggested by ECU tester. No change, garage suggested pattern-part caliper the cause so genuine Audi one fitted.

OK for 6 weeks then re-occurred.

Had parking brake switch changed, no change.

The fault never goes away by itself, when it is there, yellow flashing brake symbol and brake switch light flashing. Operating the switch most times does nothing and no noise from the brake motors. If start and drive, loud audible intermittent alarm, alternating yellow brake icon with red triangle icon and message "Parking brake is applied" and parking brake switch light flashing.

Just occasionally operating the switch clears the fault and the motors can be heard working.

I now am in the habit of never applying the brake (automatic so car won't move). But most times now, despite leaving the car without the brake applied, next time I use the car the yellow symbol, flashing brake switch light come before even starting the engine.

Thankfully only twice have I found the brake actually applied and won't release. Some time later have been able to release it.

I have tried a reset found on the web of applying the switch down for 7 seconds then up for 7 etc. Also tried battery disconnect.

I have attached a full VCDS scan.

After a battery, 2 caliper-assemblies and wiring-loom and over £3k, no further forward. An ECU would be over £2k.

Help please, the alarm blaring away in the car is driving me mad.

Love the car but.....

Audi-A3-8V-Jul2026.txt

Hi shame I can't read the posted scan as it won't scroll, maybe its me, you seem to have replaced most everything as per faithfully given advice which I would not concur with, A. what are called pattern/aftermarket callipers are actually refurbished O.E.units, there is no unlimited supply of new units, B, the ABS unit has nothing to do with the handbrake as that operates electromagnetically and requires no assistance from fluid generated by the ABS, you have replaced a loom component therefore in my humble opinion this and the replacement of the switch would lead me to consider the handbrake control module, you should consult an auto electrician before condemning the unit as they are not cheap and need coding in, the problem with these vehicles is the electrics are far to complex and unfortunately the dealers will string you along buying parts forever, its making them rich, they have a system called Odis which can test any part of the cars electrics and identify wiring/module faults but won't do that as its far more fun getting you to replace the car in bits.

Steve.

Concur with Steve. Very frustrating. Given you're in £3k deep, absolutely nothing wrong with taking a closer look at the parking brake module. It lives under the central console behind the parking brake switch, etc.

Copy of the section from VCDS, for reference.

Just to be clear - when caliper was changed, was old EPB swapped over, or was the electric handbrake unit new too?

Edited 5 hours ago5 hr by spartacus 68

Thank you both Stevey and Spartacus very helpful of you.

Steven, I just downloaded my original VCDS attachment from this site and that scrolls OK, so who knows why yours won't; another gremlin!

I have attached an idiot's guide I found on the EPB which does refer to the control module you referred to but I understand that on my A3 8V, an MQB platform vehicle, this module is integrated into the ABS ECU.

The VCDS coding section for the EPB control unit is 53, but this does not appear in my VCDS log which supports the suggestion that the EPB function is now within the ABS ECU at 03 coding.

AudiParkingBrake.pdf

Okay, re-read the VCDS scan. Module J104 is indeed the ABS module, but the faults relate to the parking brake (right), specifically implausible signal and electrical failure.

When the caliper was swapped out for a pattern part then genuine Audi, did it come with brand new plug and play EPB, or was the original EPB swapped over?

ABS module seems unlikely, why just rear right, why not left?

They are sensitive bits of kit, especially if they have been ‘jumped’ in a previous life to change pads with separate 12v source. VCDS has specific procedure for pad changing, plus it’s recommended to keep power to the battery with a trickle charge on pad swap over.

This may or may not be useful, but I rebuilt the brakes on my B8 A4 Allroad. Audi don’t even stock parts for rebuild, apart from a caliper square seal and dust boot. Budweg kits (Autodoc) come with ‘o’ rings that seal the caliper splindle on both sides. This is what stops water ingress. You need long needle nose circlip pliers to swap out. If you’ve got a new Audi OE brake caliper, then this will be fine. However if old EPB was simply bolted on, who knows? It’s held on with Torx screws.

Another open given you have VCDS is to post the log on RossTech forum if you haven’t already done so.

Looked on LLL parts for the parking brake module but no luck. That’s not to say it isn’t there though. Appreciate that some models of A3 use the ABS module.

Edited 31 minutes ago31 min by spartacus 68