Help Please - My A4 is Driving Me Mad

[Monzta]

Having been off the road for three weeks I thought I'd finally solved my problems. I'd fitted a secondhand Central Electronic Control Module and the car was starting and ticking over fine and my wipers were once again working.

I cleared all the codes then took it for its first drive today and within a quarter of a mile the Check Engine Light was on and the car was in limp mode so I turned around and drove straight home. I ran VCDS-Lite and it came up with the fault codes below (highlighted in bold).

I'm not too bothered about the SatNav and Radio codes, it's the engine, ABS and wiper ones that are the issue.

Any help in decyphering them and pointing me in the right direction would be hugely appreciated. I'm self-employed and need this car working ASAP.

I've Googled the various fault codes but I'm not getting any particular remedies that tie in with all of them except perhaps there being a problem with the engine wiring loom.

My car is a 2004 1.9 TDI SE Avant with the AVF engine.



VCDS-Lite Version: Release 1.2

Thursday, 22 August 2019, 13:03:54:45583



Chassis Type: 8E - Audi A4 B6

Scan: 01,02,03,08,09,0F,11,15,16,17,18,36,37,45,46,55,56,57,65,67,69,75,76,77


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Address 01: Engine Labels: 038-906-019-AVF.LBL

Controller: 038 906 019 LJ

Component: 1,9l R4 EDC G000AG 5934

Coding: 00001

Shop #: WSC 63251

VCID: 6AA7F3A40567

WAUZZZ8E54A227828 AUZ6Z0D0045638

5 Faults Found:

17932 - Fuel Pump Relay (J17): Open or Short to Ground

P1524 - 35-00 - -

17849 - EGR Valve (N18): Open Circuit or Short to Ground

P1441 - 35-00 - -

19561 - Valve for Intake Manifold Flap (N239): Open or Short to Ground

P3105 - 35-00 - -

18027 - Glow Plug Relay (J52): Open or Short to Ground

P1619 - 35-00 - -

17957 - Boost Pressure Regulation Valve (N75): Open or Short to Ground

P1549 - 35-00 - -

Readiness: N/A


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Address 02: Auto Trans Labels: 01J-927-156.LBL

Controller: 8E2 910 155 B

Component: V30 01J 1.9l PD RdW 3271

Coding: 0000001

Shop #: WSC 00178

VCID: 263FC794D1FF

No fault code found.


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Address 03: ABS Brakes Labels: 8E0-614-517.LBL

Controller: 8E0 614 517

Component: ABS/ESP front 3429

Coding: 04259

Shop #: WSC 06435

VCID: E5BD00986C79

1 Fault Found:

01826 - Sensor for Steering Angle (G85); Supply Voltage Terminal 30

35-10 - - - Intermittent


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Address 08: Auto HVAC Labels: 8E0-820-043.LBL

Controller: 8E0 820 043 AC

Component: A4 Klimaautomat 1450

Coding: 00000

Shop #: WSC 00000

VCID: 62B79B84FD57

No fault code found.


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Address 09: Cent. Elect. Labels: 8E0-907-279-8E2.LBL

Controller: 8E0 907 279 F

Component: int. Lastmodul RDW 0517

Coding: 00001

Shop #: WSC 00000

VCID: 351D10D81C59

1 Fault Found:

01753 - Windshield Wiper Motor (V) Stage 1

31-10 - Open or Short to Ground - Intermittent


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Address 15: Airbags Labels: 8E0-959-655-84.LBL

Controller: 8E0 959 655 J

Component: Airbag 8.4EP 1002

Coding: 0010602

Shop #: WSC 63251

VCID: 3E0F0FF4296F

No fault code found.


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Address 16: Steering wheel Labels: 8E0-953-549.LBL

Controller: 8E0 953 549 N

Component: Lenksáulenmodul 0611

Coding: 00042

Shop #: WSC 63251

VCID: 3E0F0FF4296F

No fault code found.


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Address 17: Instruments Labels: 8E0-920-9xx-8E2.LBL

Controller: 8E0 920 950 M

Component: KOMBI+WEGFAHRS. RB4 D42

Coding: 00401

Shop #: WSC 00001

VCID: 33192EC0122D

WAUZZZ8E54A227828 AUZ6Z0D0045638

No fault code found.


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Address 37: Navigation Labels: None

Controller: 8E0 035 192 Q

Component: RNS-E HIGH EU H73 0650

Coding: 0301117

Shop #: WSC 06335

VCID: 32172BC4ED37

2 Faults Found:

00857 - CD Changer Unit (R41)

004 - No Signal/Communication

00466 - Control Module for Steering Column Electronics (J527)

008 - Implausible Signal


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Address 45: Inter. Monitor Labels: 8E0-951-177.LBL

Controller: 8E0 951 177

Component: Innenraumueberw. 0704

Coding: 00001

Shop #: WSC 00000

VCID: EBA976A08A9D

No fault code found.


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Address 46: Central Conv. Labels: 8E0-959-433-MAX.LBL

Controller: 8E0 959 433 BC

Component: Komfortgerát T3B 1412

Coding: 01931

Shop #: WSC 73430

VCID: 7399EEC052AD

No fault code found.


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

Address 56: Radio Labels: None

Controller: 8E0 035 192 Q

Component: RNS-E HIGH EU H73 0650

Coding: 0301117

Shop #: WSC 06335

VCID: 32172BC4ED37

2 Faults Found:

00857 - CD Changer Unit (R41)

004 - No Signal/Communication

00466 - Control Module for Steering Column Electronics (J527)

008 - Implausible Signal


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Address 76: Park Assist Labels: 8E0-919-283-8E2.LBL

Controller: 8E0 919 283 A

Component: Parkingsyst. A4 RDW D08

Coding: 01114

Shop #: WSC 63251

VCID: 2E2F3FB4F90F

No fault code found.


End --------------------------------------------------------------------------------------------------

 

[SemedoB6]

Hey buddy..
The abs fault isn't anything special and it can be calibrated using vcds. Just don't remember how but can easily find it in a Google search..
And if your wiper is still working I'd say you can just clear the code and it'll be all good..

About your engine codes. Write them all down or take a pic so you know what they had and clear the codes and take it for a spin. If they return rescan and take notes if they are the same or not.
If they return I'd say you'll need to replace the sensor showing faulty.
I'd start with the n75. I bet that's the one putting your engine into limp mode.
If you look down somewhere next to the turbo you'll see a sensor with 3 vaccum hoses. That's the n75.

Sent from my SM-N960F using Tapatalk

 

[Monzta]

Thanks again for that.

I can't help but feel this is all water ingress based.

A few weeks ago I lifted the carpets in both front footwells just to check for water as I had a leaky A6 a few years ago. The passenger side was dry but the driver's side was damp. I lifted the carpet to start the drying process as this was during the recent heatwave. I checked the plenum area for water, the drain holes were all full of gunk so I reckon it had flooded at some point. I found that the gasket under the ECU housing was damaged so that explains the water in the drivers footwell. I then ran out of light so I put a cover over the car and called it a day. Typically the heatwave took a break that night and we had torrential rain all through the night and all next day. My car cover blew off andthe rain came through the open ECU hole straight into the drivers footwell, all over the electrics (hence why the CEC module was knackered) and ran all the way to the back of the footwell by the rear seat.

When the weather got better I dried the car out, fixed the leaking ECU gasket and put everything back together.

When it next rained my wipers packed up and then a few days later the car stalled, went into limp mode and wouldn't start again without immediately stalling. The new CEC module I fitted the other day seemed to have fixed things, the wipers worked again and the car started and ran nicely. But today, the first drive resulted in the CEL coming on again.

I had cleared all the codes last night before I drove the car this morning.

Before I start buying sensors and modules I'd better give the wiring under the ECU housing and the fusebox a good look over.

 

[SemedoB6]

I understand. Its annoying having problems and not finding the source.
Go over the wiring and then you'll be able to take proper course if it's wiring related or not.
Also, under the battery there's a grommet that can be removed so that the water can drain to the ground when it's raining.
I removed from my b6 before I had any problem with water ingress.

Sent from my SM-N960F using Tapatalk

 

[Monzta]

Well I've looked at the wiring in the ECU box and underneath into the interior beneath the dash. I couldn't see anything obvious but I sprayed as many of the connections that I could reach with WD40, cleared all the fault codes and I'll drive around the block tomorrow and see what codes come back.

I cleaned out the drain holes under the battery and the servo a few weeks ago.

 

[Monzta]

I've bought an N75 valve today, should arrive after the bank holiday. See if that improves things.

 

[Monzta]

Well spraying all the connections seems to have done the trick (I hope). I cleared all the codes and went for a test drive, did about 10 miles and no more CEL or limp mode. When I got home I did another Auto-Scan and all the engine codes were gone.

So it was a bad connection somewhere either in the relays in the ECU box or under the dash where the water got in. I'll give it all another spray of WD40 tomorrow then put it all back together again and hope that's it sorted finally.

 

[SemedoB6]

Great news pal. I'm hoping everything stays clear and you enjoy your machine..

Sent from my SM-N960F using Tapatalk

 

[Monzta]

Cheers bud, and thanks for all your advice.

 

[SemedoB6]

Really wasn't a problem. I'm glad I could help.

Sent from my SM-N960F using Tapatalk

 

[Monzta]

Well that didn't last long. I gave everything another going over with WD40 then put everything back together. Before refitting all the plastics at the base of the windscreen and attaching the wiper arms I took it for another trip around the block. I got a hundred yards then the car stalled and the CEL came on again. Nadgers!

Anyway, another Auto-Scan showed the same five error codes. I took the plastic ECU cover off whilst I had the engine running and the slightest touch to one of the parts of the loom leading to the ECU made it stall again. This takes me full circle back to when the problem began nearly a month ago. I noticed then that touching that same part of the loom caused the car to stall (see the video). I think I may have caused damage to the loom when trying to get that connector off the ECU. I didn't know then that you had to grind off the two bolts and then slide the ECU out of its armoured box (what's all that about?)



So, I need to find another one of those smaller ECU connections and a length of the loom and a good auto electrician to either find the specific wire or wires that are broken or cut off the existing connector and solder in the replacement.

 

[stevey83]

You've definetly got a snapped wire in there somewhere. Can this part of the loom be bought from a scrappy? Otherwise its a case of opening the wiring and checking the wires.

 

[Monzta]

I think it's time to find a decent auto electrician who's better with a multimeter and a soldering iron than I am.