Audi 80 Vag com results

[bagpipingandy]

Hi all, i need to pick you brains,
I have read fult codes on an Audi 80 coupe 2.6V6

it irratically starts running very rough, uncontrolable at tickover stalling and spluttering wildly, then all of a sudden after a few starts, it runs ok for a while (can be up to 1 week) then starts the crazy spluttering (not driveable under spluttering!!)

run my VCDS & found these faults:

Address 01: Engine
Control Module Part Number: 4A0 907 473 D
Component and/or Version: 2,6l V6 MPFI HS D05
Software Coding: 00062
Work Shop Code: WSC 06317
2 Faults Found:
17978 - Engine Start Blocked by Immobilizer
P1570 - 35-10 - - - Intermittent
00575 - Intake Manifold Pressure
04-10 - Mechanical Malfunction - Intermittent
Readiness: N/A

i am not too woried about the imobiliser but i believe the intake preassure error could cause the running rough symptoms
i cleared the faults and no faults came back but i understand the Audi 80's can be slow to log and i obviously need the problem to orrur again,

before it happens again does any one have an incline what it could be, no obvious leaks at the inlet, what about faulty MAF sensor, or other?

any info appreciated,

Andy

[juliuscd]

Could be fuel filter? These get choked over time and are not mentioned in any service schedules. My Audi has the same symptoms and I will be changing the filter over the weekend. If it works I'll let you know.

[juliuscd]

Well the fuel filter wasn't the problem! Looking at posts all over the internet I concluded that the problem might lay with Relay 30 which is prone to 'dry joints'. Hard to see, but there was microscopic cracking in the solder where components are attached to the circuit board. I resoldered four joints and took the car for a run - the difference is amazing! Apparently this is a common problem affecting all VAG digifant equipped cars. I hope your fix is as easy. Kind regards.

[bagpipingandy]

Thanks for the reply, i also have the same post in the Audi 80 section and have confused someone sorry for this!!,

thanks for the fuel filter response i will rule it out for now, it is like an air intake issue the second i touch the throttle it likes it even less,

where can i find relay 30? and where did you do the soldering, In the relay? or where the relay is mounted?

Andy

[juliuscd]

Relay 30 controls the ECU. On the Audi 80 you will find it under the steering column by removing the little cubbyhole/shelf thingy (8mm bolts). You'll need a torch because its tucked up high inside.
Here's a link describing relay repair - you will need to prise the cover off.

http://www.1600i.de/1600i-elektronik...heECUrelay.htm

Hope this helps.

[zollaf]

[quote=bagpipingandy;285285]Thanks for the reply, i also have the same post in the Audi 80 section and have confused someone sorry for this!!,

no need to apologise for confusing me, its very easily done. glad it sorted it. will be checking my relays soon.

[bagpipingandy]

Hi Juliuscd,
Relay 30 sounds like my next best option. looking out my soldering iron as we speak,
also "unfortunetly" the car started and run perfectly today!! i will try wiggling this relay to see if the rough idle comes back!!

i will inform you how i get on!!

[bagpipingandy]

Update on the Audi 80 2.6 V6 Running issues,

I cannot find relay 30 and doubt if i even have it!!

any idea if the 2.6 V6 has one??

I looked under steering coloumb, there are relays but none powering the ECU, also checked the passanger footwell area (UK CAR) no relays there, and none under the bonnet in the fuse box Either. in the fuse box just under the windscreen the fuel pump relay is there but no Relay 30, can any one advise if the 2.6 V6 has one? and where it should be??

car running fine just now but i haven't changed anything!!, i know it will come back if i run it for a while,

next question, is is there a MAF sensor on th V6 there is on my other cars but nothing on the intake ducting at all!!

where is this intake manifold pressure sensor My VCDS has logged more than once??

almost having to go to Audi dealer but know they will not persist as much as me!!

any info on a MAF, relay 30, possible solutions for the poor idleing & where the intake pressure sensor is, will be greatly appreciated

Andy

[scotty33]

Hi

I saw your other post, I don't think the v6 has Relay 30 - mostly a 2litre 8 valve problem and the 2.6 models do not have a MAF sensor.
I do not know where the Manifold pressure sensor is located, but if it can't be found anywhere on the intake system, it may be inside the ECU? This is installed on the bulkhead in front of the glovebox. If there is a vacuum line going into this, well you found it!

[juliuscd]

Tech Service Bulletin 94/02
AAH V6 Engine Cars - Diagnostic Trouble Code 00560
> Vacuum Hoses
> EGR Valve frequency valve malfunction
> EGR N18 Valve malfunction
> Auxillary Fuse 28 malfunction/poor contact
> EGR Temp Sensor wire loose
> EGR Temp Sensor malfunction
Tech Service Bulletin 95/04
AAH V6 Engine Cars - Diagnostic Trouble Code 00537/2341, 00554/2331
> Rubber elbow shaped hose may split causing a vacuum leak - inspect and replace if necessary with pt no. 049 133 783 (this attaches to inlet manifold)