Park brake & other intermittent problems, advice wanted

[dewitts]

Ok so i've had a passat b6 estate before and have had a failure in the park brake motors so am familiar in how it works, what fails, how to get the thing off if it dies etc.....

I've just bought a 2008 passat b6 estate again and the guy I bought it from took it in part ex for another car and put it up for sale as he has a new lease car for work.

The guy was told the previous owner had put new rear callipers on (and they do look new from a quick glance) and had the front anti-rollbars & wishbones etc done recently.

On test drive, the park brake & auto hold all worked fine, released as it should on pulling off. Cruise control worked fine (which it doesn't when there's a fault with the park brake) however I did kind of feel that one side releases before the other.
I also noticed that there's a little knock from what I believe is the drivers side. It's not always present when going over a speed bump or mounting a kerb but you can hear it when going over little bumps like changing surface, manhole covers, where they've dug the road up and re-filled it. The stuff you barely feel in the car creates this knock whereas speedbumps do not.

So lets start with the Park brake...

Initially it releases when pulling off, auto hold works ok then after a few miles it pops up 'PARK BRAKE FAULT . CONSULT OWNERS MANUAL'
Both brakes appear to be working and you can hear the motors. The car is held on a steep hill. Apart from not releasing evenly (feels like one releases before the other) there doesn't seem to be any physical problem.

I am looking for any other suggestions, but knowing the correct procedure for fitting new pads says you must use VAGCOM to tell the callipers to open fully (i'm guessing so they close evenly) the fault may be;

1. When the callipers were replaced, the callipers were manually wound back just enough to accommodate the new pads and fit over the disk.
Hook up VAGCOM, electronically wind back rear callipers and then electronically wind back on. This will even up the travel for the pads and MAY cure the fault.

2. Is there a connection issue? It's an intermittent problem, maybe the connection is corroded?
Inspect and clean if required.

3. Did they order the calliper & motor together? Was it new? (it looks clean through the wheel but may not be) Did they fit a failing part?

Any other known faults & solutions would be welcome. I haven't checked it on VAGCOM for faults as yet, I wanted to get this post up first.



The knock.....

So going on the blind belief that this work has been done and noticing the knock, I pointed it out to the seller and wondered what it was.
I tried rocking the engine to try and hear if it's the mounts (seems solid) there's no rattle from the engine at idle or when you rev it. (so not big end or small end or engine related knock).
I did manage to re-create the noise by bouncing the car at driverside wheel arch (pushed down on whole car repeatedly standing by the front wheel)

The suspension seemed to travel as it should (down, up just past it's original starting point and back to starting point. No continuous bounce) It sounded like it was close, not in the bottom of the engine bay.
The seller said he thinks it's a top mount, priced one up on whatever parts site it was for £25.

Is it likely to be this? Is it an easy replacement?

Please no comments like take it to a garage and get it checked, yes that's the obvious thing to do but this is my 1 day off and it's meant to be travelling a 400 mile round trip on Friday.
We might be able to squeeze it in during the week if my missus can get time but she uses the car for work so cannot be without a car so wanted to diagnose the knock before taking it to a garage and hopefully solve the park brake fault myself.

Thanks for any input

[dewitts]

UPDATE:

So checked for faults and found a boat load, seems that my fault lies with the Clutch position sensor which I believe is a non-replaceable part inside the Clutch Master Cylinder.
Can someone confirm this?

Anyone know how long this would take to swap out in a garage?
Part is £53 on ebay but not looked elsewhere as yet.

Took the car for a run, used the park brake several times, appeared to work normally and resetting the callipers has evened out the release as I expected.

Still need to try looking for the knock and have another test run to see if the park brake fault returns and re-do diagnostics.

Sunday,28,October,2018,14:22:31:07592
VCDS -- Windows Based VAG/VAS Emulator Running on Windows Vista x86
VCDS Version: 18.9.0.2
Data version: 20180927 DS296.0
Ross-Tech: Home




VIN: WVWZZZ3CZ8E123847 License Plate:




Chassis Type: 3C (3C0)
Scan: 01 03 08 09 15 16 17 19 25 42 44 46 52 53 56 62 72


VIN: WVWZZZ3CZ8E123847 Mileage: 238210km-148016miles


01-Engine -- Status: Malfunction 0010
03-ABS Brakes -- Status: Malfunction 0010
04-Steering Angle -- Status: OK 0000
08-Auto HVAC -- Status: OK 0000
09-Cent. Elect. -- Status: OK 0000
15-Airbags -- Status: OK 0000
16-Steering wheel -- Status: Malfunction 0010
17-Instruments -- Status: OK 0000
19-CAN Gateway -- Status: OK 0000
25-Immobilizer -- Status: OK 0000
42-Door Elect, Driver -- Status: OK 0000
44-Steering Assist -- Status: OK 0000
46-Central Conv. -- Status: OK 0000
52-Door Elect, Pass. -- Status: OK 0000
53-Parking Brake -- Status: Malfunction 0010
56-Radio -- Status: OK 0000
62-Door, Rear Left -- Status: OK 0000
72-Door, Rear Right -- Status: OK 0000

-------------------------------------------------------------------------------
Address 01: Engine Labels: 03G-906-018-BKP.clb
Part No SW: 03G 906 018 FG HW: 03G 906 018 FG
Component: R4 2.0l PPD1.5 G 0907
Revision: --H45--- Serial number: VWZCZ000000000
Coding: 0000072
Shop #: WSC 05311 000 08193
VCID: 6FEDEFCF7E80A4323C-803A


1 Fault Found:
000564 - Boost Pressure Regulation
P0234 - 006 - Limit Exceeded (Overboost Condition) - Intermittent
Freeze Frame:
Fault Status: 00000001
Fault Priority: 5
Fault Frequency: 4
Reset counter: 20
Mileage: 237945 km
Time Indication: 0
Date: 2000.00.00
Time: 14:09:04


Freeze Frame:
RPM: 3584 /min
Torque: 200.0 Nm
Speed: 58.0 km/h
65.91 %
Voltage: 14.35 V
Pressure: 1810.5 mbar
Pressure: 2300.4 mbar


Readiness: N/A


-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: 3C0-614-109-C4.clb
Part No SW: 3C0 614 109 D HW: 3C0 614 109 D
Component: J104 C4 440 V2 0003
Revision: --020--- Serial number: 00000776487066
Coding: 0001291
Shop #: WSC 05311 000 00000
VCID: 1F4DDF0FCEA074B2CC-804A


1 Fault Found:
00473 - Control Module for Elect. Park/Hand Brake (J540)
013 - Check DTC Memory - Intermittent
Freeze Frame:
Fault Status: 00101101
Fault Priority: 6
Fault Frequency: 129
Reset counter: 69
Mileage: 235180 km
Time Indication: 0
Date: 2000.00.00
Time: 14:54:44


Freeze Frame:
Speed: 34.0 km/h
Hex Value: 0x00B1
Voltage: 13.75 V
Bin. Bits: 00011111
Count: 101




-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
Address 16: Steering wheel Labels: 3C0-953-549-SW20.lbl
Part No SW: 3C0 953 549 AD HW: 3C0 953 549 AD
Component: J0527 0020
Revision: 00026000 Serial number: 3C9953507BA
Coding: 0000014
Shop #: WSC 05311 000 08193
VCID: 6ED3F2CB798AAD3A37-803A


1 Fault Found:
00888 - Wiper Switch for Intermittent Operation (E22)
014 - Defective - Intermittent


-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
Address 53: Parking Brake Labels: 5N0-907-801.clb
Part No SW: 3C0 907 801 J HW: 3C0 907 801 J
Component: J540 EPB3 VW-09393 0009
Revision: 008 Serial number: 00000000235380
Coding: 0000057
Shop #: WSC 05311 000 08193
VCID: 2959C1D780E48A02A2-807C


1 Fault Found:
03182 - Clutch Position Sensor (G476)
008 - Implausible Signal - Intermittent
Freeze Frame:
Fault Status: 00101000
Fault Priority: 3
Fault Frequency: 41
Reset counter: 68
Mileage: 237181 km
Time Indication: 0


Freeze Frame:
Voltage: 13.70 V
Count: 38
Speed: 76.0 km/h
Hex Value: 0x1260
Hex Value: 0x0004
Hex Value: 0x0101




-------------------------------------------------------------------------------

[DieselMonster]

If it's a clunking sound, it will be the drivers side droplink. I can't help you with the clutch position sensor, it isn't a hard fix though. Just check online for the part, see how it is mounted by looking at the part you bought and swap it over. I don't know whether you need vcds to do adaption but I doubt it.

[dewitts]

Just had some random foreign guy stop and try helping, nice of him to look but language barrier was a nightmare.
OK so had the wheel off, can't see anything obvious, drop link 'APPEARS' to be new, has new nuts and no corrosion on there.
I got a pry bar out and tried moving a few things including the droplink but no noise.

Another thing I just thought MAY be relevant, There does seem to be a rubbing noise or bearing rub noise when turning full lock!
I have checked the wheel for freeplay, but doesn't seem to be any.

[dewitts]

Just come back from another run, Can't make the Park brake fault come back.
No faults showing on VCDS.

Stopped in a car park and decided to shake the steering, got the same knocking noise from shaking it so think that's where my problem lies.

Going to follow up on the Clutch sensor problem and confirm it's in the master cylinder.

[dewitts]

Gutted, new master cylinder fitted and now the light is constantly on, can't get rid of the fault at all now.

VCDS still says it's the clutch position sensor.

The subtle knock has turned out to be the steering rack, £400 + vat + 3 hours labour

[dewitts]

I've had the master cylinder replaced a while back now and still have an issue with the parking brake.
I kind of assumed that it may be a wiring issue as the master cylinder & clutch position sensor have been replaced and I have not had any issues with staring the car since doing so (did play up occasionally)

I have since been advised that it might be a case of the new sensor needs programming.

Does anyone know how to do this? Or have a link to a page so I can do it myself??

[philipharmes]

I don't think the G476 needs any programming, there's no reference to it anywhere on Google.

Before you can start the car the clutch needs operating, so would have thought this G476 sensor outputs to both the ECU & PB, so probably not a clutch sensor fault, but could be wrong.

If you look at his link which is for A4 wiring ( probably similar to the Passat ) https://www.audi-sport.net/xf/thread...-fault.233505/ half way down the post shows the wiring for the G476.
One wire goes to the PB module pin T30a.

If you connect a DVM to T30a with the ignition on you should see a change of voltage when the clutch is depressed.
If you see that, it points to the problem being in the PB module.
If you don't see a voltage change try disconnecting the PB module, as a fault in there could be dragging the voltage down.

[dewitts]

Thanks for your reply Phillip.

Whilst having issues with the Park brake, I was also having issues starting the car intermittently ( whilst clutch was down it said 'depress clutch to start')

Since changing master cylinder and therefore position sensor I have not had this issue whereas it was occurring at least once a day.

Before I changed the master cylinder I was able to clear the fault but since changing I can't.


Perhaps i'll try finding that connection and testing it but it does seem odd doesn't it?

[philipharmes]

So it does sound like your original master cylinder did have an intermittent fault.
Did you make sure the new MC was the exact same part No.
Was it new or from breakers.

It would be best if you could get the correct wiring diagram for the Passat in case it is different.

Also on the Audi diagram the wire from G476 pin 5 only goes to the parking controller.
Two other wires pins 2 & 3 go to the ECU.
So although they will probably all use a single switch in the master cylinder they could have isolated outputs to the PB & ECU.