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bagpipingandy
11-12-2008, 09:56 PM
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
12-12-2008, 08:22 AM
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
17-12-2008, 12:22 AM
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
18-12-2008, 04:57 PM
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
18-12-2008, 07:18 PM
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/relais-steuergeraet/CheckingandrepairingtheECUrelay.htm

Hope this helps.:D

zollaf
18-12-2008, 08:20 PM
[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
18-12-2008, 10:29 PM
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
21-12-2008, 11:12 PM
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
22-12-2008, 12:18 AM
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
22-12-2008, 12:40 AM
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)

bagpipingandy
22-12-2008, 09:57 AM
hi Scotty33,

at least i am not going mad, i am sure i would have found them if they were there, thanks for the no relay 30 and no MAF info at least that rules this out.

I saw the vacum hose on the ECU I will check this for leaks thanks for the pointers,

Also thanks for the reply JuliusCD (Again!!) i will check out the list you attached,

i will let you know,

regards

Andy
regards

scotty33
22-12-2008, 07:53 PM
Andy,

This is the infamous relay 30, I took this one from a 2l passat, but the Audi 8v ABK engine also uses the same part,

http://i246.photobucket.com/albums/gg104/scotty33_bucket/SSM10693.jpg

http://i246.photobucket.com/albums/gg104/scotty33_bucket/SSM10694.jpg

bagpipingandy
03-01-2009, 09:11 PM
Happy new year by the way (hopefully solve this running issue before easter!!)

Update on Audi 80 Running issues:

for the record its a V6 2.6 ABC Engine

The intake pressure error has now been logged and cleared 4 times over the last few weeks see todays check below:

Saturday,03,January,2009,14:52:50:05805
VCDS Version: Release 805.1
Data version: 20081223

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

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
1 Fault Found:

00575 - Intake Manifold Pressure
04-10 - Mechanical Malfunction - Intermittent

Readiness: N/A.
----------------------------------------------------------------
So findings continued from previous posts:
I stripped out in footwell the ECU and removed the vacuum line from the ECU & intake manifold. No leaks on the pipe itslef much to my dissapointment (that would be too easy).
Removing the pipe stalls the car but you can get it running again (It seems to go into a get home mode) as on the VCDS with the pipe removed the software still shows a fluctuating % value for the intake manifold pressure??? and it changes when revving?, strange but perhaps the car does some assumptions due to this value being missing.

any way I can replicate similar bad running symptoms with this pipe removed by sucking to create different pressures on the ECU intake manifold sensor, so put pipe back on car still run slighly rouch until i cleared fault codes then it takes actual value from the vacuum pipe, and runs fine, all good so far,
This would make me think the fault is the pressure switch in the ECU or the ECU itself. i removed the ECU and took of the cover to ensure there is no obvius leaks (pipe inside the unit) and check for any damage to the Printed circuit board, no sign of any problems with the above.

I am thinking of looking for a replacement ECU would any one agree? or am i missing something?

Looking at the VAG No of my ECU (4A0 907 473 D) there are many for sale of this number but also many with a different letter at the end obviously the "D" is what i would need but what is the difference? could i not change the coding with my VCDS with one with say "A" or "T" there is only one "D" on E-bay but i would be cheaper going to Audi??.
I have still to get a quote from Audi dealer and they can tell me if it is superceeded with a new letter.

also if i can find a "4A0 907 473 D" when i fit it will i need to code it using VCDS to the original ECU software coding and workshop code as above or do these values only suit this ECU?

any advice or any one who has changed a ECU your thoughs greatly appreciated,

Andy

scotty33
04-01-2009, 05:06 PM
When you had the ECU opened up, did it look like the MAP sensor could be replaced? I think the ECU is made by Hitachi, you might be able to track down the pressure sensor and replace it yourself?

I don't think there would be any issues with swapping in an identical ECU. These cars as far as I know, do not have the immobiliser in the instruments, so not linked to the ECU.

There can be significant differences in ECU's even when only the suffix letter changes. EG my early 1990 20v has a part no. ending suffix B. The later 20v had same part no. but ending in suffix D. They use a totally different plug/ interface.

Crasher
04-01-2009, 05:22 PM
ECU 4A0 907 473 D is also compatible with 4A0 907 473 K and 4A0 907 473 T.

If the vacuum hose from the engine to the ECU is perfect (allowing flow, not just leak free) then I think you have a faulty ECU.

Remember that a replacement will have to be coded in. This is carried out in Immobiliser 25, Adaptation 10, read and save.

scotty33
04-01-2009, 07:40 PM
Remember that a replacement will have to be coded in. This is carried out in Immobiliser 25, Adaptation 10, read and save.

So the immobiliser is linked to the ECU?:confused:

bagpipingandy
04-01-2009, 09:32 PM
Thanks for the info guys,

The MAP sensor could be changed quite easily and i did think of this, but if i can find the same ECU number i will go with that 1st,

i will have to look into the quote from Crasher "Immobiliser 25, Adaptation 10, read and save".

Will I need anything from Audi? or can i read the info at the original ECU address and then copy the data to the replacement ECU.
I am not fully fluent at VCDS yet and notice some imobiliser modules ask for this 7-digit PIN/SKC what is this?

Many thanks for all your input, off searching for an ECU, i will give an update soon

regards

Andy

bagpipingandy
04-01-2009, 09:34 PM
So the immobiliser is linked to the ECU?:confused:


No worries Scotty, i wouldn't know this, also the ECU is manufactured by hella, but i knew, you knew that!!

Crasher
05-01-2009, 12:04 AM
So the immobiliser is linked to the ECU?:confused:


Well yes, how else would it work? :D The ECU comms with the diagnostic port through the immobiliser.

scotty33
05-01-2009, 07:29 PM
Well yes, how else would it work? :D The ECU comms with the diagnostic port through the immobiliser.


My mistake, you live and learn!

I had the original alarm/immobiliser on my coupe. It was a Scorpion 3 way type affair. Possibly a dealer fit rather than factory?
I knew the later coupes had a factory immobiliser, I wasn't aware of how it is integrated with the ECU.

I know the 96> cars - A4's etc have the full immobiliser in the instrument cluster with a transponder in the key and a key reader coil near the ignition switch. I know the Security Key Code (pin) is needed for getting spare keys recoded. As I understand it the older cars (before 2001??) have a 4 digit SKC, later have the 7 digit code. I don't know if it is IMMO I? if it is this may help:

http://wiki.ross-tech.com/index.php/Immobilizer_I_ECU_Swapping

scotty33
05-01-2009, 07:44 PM
No worries Scotty, i wouldn't know this, also the ECU is manufactured by hella, but i knew, you knew that!!

I didn't know this, thought it was Hitachi! I still think the processor inside could be Hitachi, but may well be wrong here..

2.8 ECU's

http://www.12v.org/engine/index.php?section=hw

If it is Hella made, then maybe the MAP sensor is a Bosch or Pierburg part? if so should not be too hard to obtain one? for what it's worth I just replaced one on my passat, which I guess is a totally different type, but was approx £40.

bagpipingandy
05-01-2009, 09:21 PM
HI Scotty,

there may well be a Hitachi one but my one is Hella and hella PCB inside,

i have traced someone who says they have the same ECU for sale, A new one priced today at Audi Dealer £420!! this one for sale a lot less, but does it work!!, you pay your money you take your chances!!

i will try the whole ECU 1st if i can work up the courage to disconnect the old one!!

bagpipingandy
11-06-2009, 09:09 PM
Hi all long time since i updated this thread!!

the Audi coupe has finally had the new ECU fitted last month, (£30 from E-bay) , We paid Audi £30 to code the imobaliser in as they were not to forthcoming giving me the 7 digit code and other info required but the out come is good as the car is running fine no stalling or rough running, no MAP sensor codes cropped up so i can now assume it was faulty on the other ECU, phew!! Its been off the road due to work required for MOT and cash flow but all passed and running well for a few weeks now. many thanks for all input over the last 8 months, or more now to think of it!!

Andy