ABS electrical problems

[s4AvantChris]

I have an ABS problem on my B6 S4 which is driving me nuts.
Engines starts fine and car runs well. However, ABS light (solid) and brake light (flashing) on dash.
Also noticed that the brake lights are on permanently.

Tried VCDS and it will not communicate with the ABS module.
Looked at many posts on forums and have changed brake light switch, ABS electronic module, even central electric unit. No change.

One of the errors on VCDS is,
00625 - Vehicle Speed Signal
27-00 - Implausible Signal
So I checked MVB as follows,
Central Electric 014.2 326.4km/h
Engine 005.3 0km/h
Instruments 001.1 326.0km/h

Not sure where it's getting these speed values from? Could it be that it won't communicate with the ABS module when it thinks the speed is so high?

Would really appreciate some pointers.

Chassis Type: 8E (8E - Audi A4/S4/RS4 B6/B7 (2001 > 2008))
Scan: 01 02 03 08 09 0F 11 15 16 17 18 25 36 37 45 46 55 56 57 65
67 69 75 76 77

VIN: WAUZZZ8E43A329927 Mileage: 139650km-86774miles
-------------------------------------------------------------------------------
Address 01: Engine Labels: 079-910-560-BBK.lbl
Part No SW: 8E0 910 560 HW: 8E0 907 560
Component: 4.2L V8/5V G 0030
Coding: 0011711
Shop #: WSC 63351 000 00000
VCID: 62C0A06ABEB36056E7-5102

2 Faults Found:
18057 - Powertrain Data Bus
P1649 - 008 - Missing Message from ABS Controller
18080 - Coolant Fan Control 1
P1672 - 004 - Open or Short to Ground
Readiness: 0110 1101

-------------------------------------------------------------------------------
Address 08: Auto HVAC Labels: 8E0-820-043.lbl
Part No: 8E0 820 043 Q
Component: A4 Klimaautomat 1116
Coding: 00000
Shop #: WSC 63351
VCID: 2F66195EEDE19D3E38-5102

4 Faults Found:
01592 - Air Quality Sensor (G238)
37-00 - Faulty
00819 - High Pressure Sensor (G65)
29-00 - Short to Ground
01206 - Signal for Duration of Ignition Off Time
27-00 - Implausible Signal
01312 - Powertrain Data Bus
79-00 - Please Check Fault Codes

-------------------------------------------------------------------------------
Address 09: Cent. Elect. Labels: 8E0-907-279-8E2.lbl
Part No: 8E0 907 279 F
Component: int. Lastmodul RDW 0517
Coding: 01011
Shop #: WSC 63251
VCID: 356A2B360FBDA7EE72-4ACE

1 Fault Found:
01312 - Powertrain Data Bus
79-00 - Please Check Fault Codes

-------------------------------------------------------------------------------
Address 15: Airbags Labels: 8E0-959-655-84.lbl
Part No: 8E0 959 655 B
Component: Airbag 8.4EP 2000
Coding: 0010702
Shop #: WSC 63351 000 00000
VCID: 36682C3A42BBACF67B-50E6

No fault code found.

-------------------------------------------------------------------------------
Address 16: Steering wheel Labels: 8E0-953-549.lbl
Part No: 8E0 953 549 N
Component: Lenksáulenmodul 0308
Coding: 00042
Shop #: WSC 63251
VCID: 3E78341A3A8B64B6A3-4ACE

No fault code found.

-------------------------------------------------------------------------------
Address 17: Instruments Labels: 8E0-920-9xx-8E2.lbl
Part No: 8E0 920 980 L
Component: KOMBI+WEGFAHRS. RB4 D36
Coding: 01401
Shop #: WSC 00010
VCID: 356A2B360FBDA7EE72-5102
WAUZZZ8E43A329927 AUZ6Z0C0013263

1 Fault Found:
01316 - ABS Control Module
49-00 - No Communications

-------------------------------------------------------------------------------
Address 37: Navigation Labels: 8E0-035-192-RNSE.clb
Part No SW: 8E0 035 192 Q HW: 8E0 035 192 Q
Component: RNS-E HIGH EU H74 0650
Revision: 04S Serial number: AUZBZ7G0048014
Coding: 0309713
Shop #: WSC 06335 000 00000
VCID: 3260102AAED3B0D657-5120

1 Fault Found:
01316 - ABS Control Module
004 - No Signal/Communication
Freeze Frame:
Fault Status: 01100100
Fault Priority: 5
Fault Frequency: 1
Reset counter: 161
Time Indication: 0
Date: 2002.02.23
Time: 20:29:19

Freeze Frame:
Bin. Bits: 0010
Mileage: 655350 km
Count: 2302
Clock: 20:29


-------------------------------------------------------------------------------
Address 45: Inter. Monitor Labels: 8E0-951-177.lbl
Part No: 8E0 951 177
Component: Innenraumueberw. 0604
Coding: 00001
Shop #: WSC 00000
VCID: 6BDECD4E1979211E54-5120

No fault code found.

-------------------------------------------------------------------------------
Address 46: Central Conv. Labels:. 8E0-959-433-MAX.clb
Part No: 8E0 959 433 BC
Component: Komfortgerát T3B 1211
Coding: 07115
Shop #: WSC 63351
VCID: 73EED52E4149F9DE9C-4ACE

Subsystem 1 - Part No: 8E2959802
Component: Tõrsteuer.FS BRM 0002

Subsystem 2 - Part No: 8E2959801
Component: Tõrsteuer.BF BRM 0002

Subsystem 3 - Part No: 8E0959801A
Component: Tõrsteuer.HL BRM 0003

Subsystem 4 - Part No: 8E0959802A
Component: Tõrsteuer.HR BRM 0003

1 Fault Found:
01134 - Alarm Horn (H12)
49-00 - No Communications

-------------------------------------------------------------------------------
Address 55: Headlight Range Labels: 4Z7-907-357.lbl
Part No: 4Z7 907 357
Component: dynamische LWR D09
Coding: 00060
Shop #: WSC 63351
VCID: 040C86F214E7CE66B5-4ACE

No fault code found.

-------------------------------------------------------------------------------
Address 56: Radio Labels: 8E0-035-192-RNSE.clb
Part No SW: 8E0 035 192 Q HW: 8E0 035 192 Q
Component: RNS-E HIGH EU H74 0650
Revision: 04S Serial number: AUZBZ7G0048014
Coding: 0309713
Shop #: WSC 06335 000 00000
VCID: 3260102AAED3B0D657-5120

1 Fault Found:
01316 - ABS Control Module
004 - No Signal/Communication
Freeze Frame:
Fault Status: 01100100
Fault Priority: 5
Fault Frequency: 1
Reset counter: 161
Time Indication: 0
Date: 2002.02.23
Time: 20:29:19

Freeze Frame:
Bin. Bits: 0010
Mileage: 655350 km
Count: 2302
Clock: 20:29


-------------------------------------------------------------------------------
Address 76: Park Assist Labels: 8Z0-919-283.lbl
Part No: 8Z0 919 283 A
Component: Parkingsyst. A4 RDW D09
Coding: 00114
Shop #: WSC 63351
VCID: 438E45EE5169095ECC-50E6

1 Fault Found:
00625 - Vehicle Speed Signal
27-00 - Implausible Signal

-------------------------------------------------------------------------------
Address 77: Telephone Labels: 8P0-862-335.lbl
Part No SW: 8P0 862 335 AA HW: 8P0 862 335 S
Component: FSE_256x BT H34 0600
Revision: 00000000 Serial number: 00000005128365
Coding: 0010722
Shop #: WSC 00000 000 00000
VCID: 75EAEB361F3DE7EEB2-50E6

No fault code found.

 

[DieselJake]

Blimey that's allot of codes, first thing I'd do is clear them and see which ones come back, sounds like something more serious like the CCU or something messing up but I could be wrong.

 

[s4AvantChris]

Sorry to say that I have cleared them and this is what comes back!

You're right. It is a lot of codes though!

 

[DrStrange]

Firstly Chris,

Lets narrow down the faults given that purely relate to the ABS.

My situation so you know where im coming from - My car starts fine with zero issues and then when im driving at slow speeds the ABS Light comes on (solid Yellow) and the traction light come on. This only happens at slow speeds and also kills the speedomoter. As in, it goes dead and doesnt record speed. It also makes the gear changes so jerky that the car feels like its going to cough me out!! After, stopping the car and starting again, its fine all over again until it happens again. Maybe 15mins later, maybe 1 hour later. Its very random.

Without having VCDS, (I know have cloned copy so wish me luck i can test) I got my guy to change the front wheel speed sensor even though it appeared to be fine. NO change in my situation at all.

So right now (having searched endlessly on all forums like you) the remainig this for you and me to do are the follows;

1. Try disconnecting and reconnecting the battery and see if its an electrical glitch. (both of us haventdone this)
2. Changing brake light switch (you have done this) but on rare occasions does this work.
3. Apprently our cars also have a Rear speed sensor ?? to change also.
4 The Dreaded ABS module itself. Now this is almost certainly the main cultprit. You mention you have done this? Are you sure? As in, you get it sent off and re-conditioned ? On countless forums, its been said that the A4's and A3's have this intermittent issue. Your fault code suggests this. ..And i've been putting this off myself hoping its not this, but all things point to it!

Lastly, and and odd ball remedy..Do you have an aftermarket HID kit installed? If yes, they are absolutely notorious for sending EM sh*t through out your car. If you place the ballast inside the light housing it will not do this. ( i made this error years ago now).

We both need to crack this so good luck and let me know what you do.

 

[s4AvantChris]

Thanks for your comments. We do certainly seem to have similar problems. Both very annoying.
I don't know if my speedo is working as I don't really want to drive the car with brake lights permanently on.

In response to your points,
1. I have disconnected the battery for 24 hours a few times to re-charge the battery. Has no effect on the problems.
2. My new brake light switch made no difference. I have however seen a few posts that suggest even new switches can be faulty and if they are installed incorrectly, they can throw errors. I followed the installation rules exactly when I put the new switch in.
3. Have not looked at either front or rear sensors.
4. The ABS module I changed to was a used model (same part code). I thought a re-manufactured unit was a big expense just to eliminate it from the errors. Looks like I'm getting close to having no other option now!
5. I have factory HID lights on my car so can't see that having any effect on this mess.

I'm still concerned that the parking assist module is showing a speed error. Any idea how to disconnect this to eliminate it?

 

[DrStrange]

Hi Chris,

Sorry for the delay.

Yes, increasingly annoying my issue is consistent, happens every day and is obvosuly quite serious as it makes the car go into a near 'limp mode' state.

What do you mean by, ''I don't know if my speedo is working as I don't really want to drive the car with brake lights permanently on''
what I meant was, does your speedo needle go dead and go to 0mph when the ABS and traction control light come on?

1. Shame, sometimes this does seem to help with 'electrical' issues.
2. Yes, but I dont doubt your skills especially if you've done it 'by the book. Is the brake light switch genuine? As in..an OEM part number? As some non oem parts arent liked by our B6 model.
3. Defintely worth a look BUT i must say, if VCDS isnt showing you codes for this, they are likely fine.
4. Actually they are supposedly the same cost. There or there abouts. An Audi Ex master Tech advised not to go the 2nd hand route even if the part number is correct as you would have to code it in with VCDS. Have you done this? I havent had time to check, but if this is my issue, i'll have to send mine off (ABS moule) and get it 'reconditioned' by a reputable company.
5. Factory HID's wont cause any interference so you can rule that one out.

At least we both are getting one step closer to the solution.

As I said, as soon as its sussed out what the issue will be, I will document it

Unfortauntely im not really savy with this. Can you clear the code and see if it comes back? Failing that, other audi forums have suggested the module could be on its way out. Does it actually effect anything?

 

[Roland Wong]

Why not try testing the Wheel Sensors using the ohmmeter and voltage checks using a Digital Multi-meter. I would test the rear ones first, because the rear seat bottom is usually easier to remove to access the sensor harnesses.

 

[DrStrange]

Thanks for the input Roland!

Chris, any news?

Sorry I've been super busy but it turned out to be the ABS f*cking module! Got it sent off and refurbished. Costed £700.

However it comes with a LIFETIME warranty now.

 

[s4AvantChris]

Youch, £700 ! That's a whole load of cash. The BBA reman service listed on fleabay is only £135. Why so much more?
I haven't looked at mine for weeks. It just sits there looking at me, getting me more annoyed. Will do something when the sun comes out.

 

[DrStrange]

Yeah, nasty sting.

Good to know that the consensus is to use BBA Reman. That's who was used for my refurb.

Are you sure Fleabay wasnt just listing generic prices?

Also, What i forgot to mention was all the other jobs the mechanic did and in my frustration, assumed £700 was for the ABS issue alone! (But it was for labour too)

 

[DrStrange]

I feel your pain!

Get to it as soon as you can. The more we procrastinate the worse it seems to get.