Vag and Dv questions!

[RickS4]

Hi!
I have some questions, and i don't found answers in many post. I received my Vagcom from ebay, it run good only when the switch is in position off… it codes my ECU but it loses connection in switch on and engine start. What is the problem? I reinstall several time the driver, the port is good.??

I had on my car 2 different dv. 1x710n passenger side and Forge 006 driver side… is can affect some things?… and is normal that the job was made like that?

Thank you very much!

[gointoscott]

What codes does your car show when its off?

Any codes to deal with abs module?

Also is your abs and esc light on all the time?


Reason I ask this question is I have seen 2 different S4's that had problems with their abs module and both had the same problem of the vag not communicating when the car was on. But if the key was off you can check for codes.

Maybe it was a coincidence that both had problems with abs, but if this also your problem then maybe its more then a coincidence.

Oh also I dont think the Dv's have anything to do with it. But I dont have any proof of that either.

[RickS4]

18058 - Powertrain Data Bus: Missing Message from Instrument Cluster
P1650 - 35-00 - -
17963 - Charge Pressure: Maximum Limit Exceeded
P1555 - 35-00 - -
16805 - Warm Up Catalyst: Bank 1: Efficiency Below Threshold
P0421 - 35-00 - -
And yes, i have abs light... problem with modul. VAG-com clear the code but when i start the car... the abs light come.
What can i do for by pass de abs modul, unplug the fuse?

thank you for your help!!

I know that the dv nothing has the problem with vag in the case of… just that I wondered whether that could cause me other problems

[gointoscott]

The max charge pressure usually is because its over boosting. Mine did that when I had the mbc turned up too high. Do you run mbc? if so turn it down. its not good for turbo's to be overboosting like that.

If you do not have mbc, then the overboosting could be from the n75 valve, this is what controls boost is defective. this does happen at times. Again if that isnt working right you will want to replace it. Also when you do over boost and it throws this code it will go into limp mode which only allows car to boost to 5psi or so which will make care feel sluggish and no power, but when you shut car off and turn back on again it will boost again.

Do you have a boost gauge? If so you will notice what I was saying about the boost.

I'm not sure about the other codes. maybe someone else can chime in onthose.

but for abs I think you can find replacement abs modules for 50 bucks, and i think they are easy to replace. once you do this i bet your vag will work correctly. im not sure if you can unplug the fuse to get it to read when car is running.

[RickS4]

Thank you for all!!

I don't have MBC at this moment on my s4.
I read that several people install in parallel with the n75 what decreases the boost spike. I will start by making a leak test before change the n75. 50$ for a ABS controler is really in bottom of what I believed. that is not worth the sorrow to make it repair
Sorry for my english, I speak French, but a understand well But English writing is sometimes hard has to understand.

Thank for the help!!
a+

[gointoscott]

Yes running parallel with mbc and n75 will clip spikes.

but if you are just running stock n75 you shouldnt see that max pressure code unless the n75 is going bad. but it would def be good to check for leaks and see if that code comes back.

[RickS4]

Thank you Gointoscott... i remove the abs fuse and i can now use Vag-com on run engine! I had make many seach on board and net... and you told me the answer in 2 secondes.

[gointoscott]

You actually helped me too. I have seen a few cases where the ecu's would quit communicting when the abs light was on. I wasnt sure if it was something related.

You helped to confirm that when the abs module goes bad it causes vag-com to not work properly.

[tgiblin]

missing message from instrument cluster - you need to recode the instrument cluster. Search the forums for it there is good info. Its on wikitech too. You need to recode block 60 from 0 to 1025 I think

[RickS4]

Thanks for all...
I make new search!