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Wolfgang, Master Vw/Audi Tech
Category: UK Car
Satisfied Customers: 4526
Experience:  15 yr Master VW/AUDI Technician Shop Foreman
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This is a tough one. My Porsche Cayenne turbo 2003 will not

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Hi, this is a tough one. My Porsche Cayenne turbo 2003 will not talk to any diagnostic computer. I've tried em all-and paid for it!
We have then looked for a gateway control unit and can't find one anywhere...
JA: What is the model of your '03 Porsche?
Customer: 4.5 turbo
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: No. It is languishing in a garage at the moment. I bought a spare gateway control unit as we thought the old one must be faulty as there is NO communication at all, even though there is power to the socket
JA: Anything else you think the mechanic should know?
Customer: Well, there is now a misfire, but it obviously can't be solved easily without some diagnosed
JA: How many miles are on the car? Is it a steady misfire? Or random?
Customer: After it gets warm, engine management light comes on and it limps then . Works fine when cool

Thanks for choosing Just Answer . I'm Wolfgang here to help!!

I am confident we can resolve your problem together. Please
understand that I don't know your skill level. In most cases when you have a problem
with the way the vehicle performs, specialized tooling is required to acquire computer
data/information or engine testing results. We didn’t build these complicated vehicles; we
just diagnose and fix them. Also understand that I can't see, smell, hear, or touch the
vehicle either, so it may take a few replies to get to satisfactory results.

Note there may be an issue where the complexity of the issue will require a Premium Service. This service will be an addition to the normal question cost. Usually it does not come down to this but keep in mind!!

I am also going to direct you with the fastest, easiest and most common things to check first. Please be
patient and permit me to do what I do best.
I also try to give all of the information you may need, expecting a “positive rating” in
return. I will also continue assisting you after you have rated me, if necessary. If there
is any reason I cannot get a positive rating, please let me know why “in advance”, so I
can go another direction for you. I am sorry you’re having this problem; I’ll help you
through it.
Below is my first answer or request for more information. If you do not understand it, or you need more information from me, or need me to go in more detail.

I do need a vin # of the vehicle and do you have an oscilloscope need to see why the can wires are not communicating correctly for the scan tool

Customer: replied 10 months ago.
Vin no is
Customer: replied 10 months ago.
Wires have been tested and there is power to the testing socket

that power is a 12 volt power to power up some scan tools. this is communication wires which have a high and low signal and must mirror each other but as a ppsitive and negative voltage. so that is why the oscilloscope is needed for testing.

let me see what i can find

Customer: replied 10 months ago.
Ok thanks! Please note that we have looked everywhere for a gateway control module, and can't find one. It's supposed to be birthing the glove box
Customer: replied 10 months ago.

note your vehicle does not have a separate gateway module . the gateway is incorporated with the instrument cluster on your vehicle!! so the communication architecture is totally different than the later cayenne's from 2006 and above!!!

Customer: replied 10 months ago.
why won't any computer talk with it then? I can't get rid of errors like suspension and occasionally abs, cruise control doesn't work, various lights ping up errors, reverse sensors don't work... And no communication! :(
Customer: replied 10 months ago.
if the instrument cluster is faulty can I replace it with a later version, say 2005/2006? I heard that you can't replace them as they need a specific code

do you have VAG COM (VCDS) by Ross Tech cable?

if not what scan tools you have?

Customer: replied 10 months ago.
I will find out. Please let me know what to do if I can't get a diagnosis. Thanks

with vag com there is a light on the cable that tells you if the can lines have an issue.

Customer: replied 10 months ago.
No issues with the can lines but the vag com will not talk with any ecu

with the vag com cable is the light green or red when plugged in?

Customer: replied 10 months ago.
It's green but flashes red when trying to connect.



Customer: replied 10 months ago.
Hi Wolfgang ! Sorry I haven't been able to get a photo yet. The instrument cluster is being sent away to be checked and possibly repaired. This will take 5 working days. I hope you can bear with me-I appreciate the advice!

ok sam!!!

Customer: replied 10 months ago.
Hey Wolfgang ! Hope you remember me?;) the instrument cluster came back with no faults, but as the engineer was building the car back up he tested it and he had some communication! The annoying bit is that the limp mode that occurs when the engine gets above 65c is not showing. Also I have no idea what the actual problems are. He has said ecu remap from tech art might be the problem, but I am reluctant to change that. I'd welcome any opinions from you, but I don't expect you to have to answer all these problems!
Many thanks
Customer: replied 10 months ago.
hopefully you can open this!

hey i do need all of the codes please on this then so i can see all what is related or not


Customer: replied 10 months ago.
Well, he has just sent them all to me:/ doesn't look good to me, but I only lift weights for a living ;)
Customer: replied 10 months ago.
The car has been in the garage for 7 weeks now
What happens if the codes are cleared and then re scanned what codes come back?
Customer: replied 10 months ago.
He has just said "the codes clear when they want to and come back when they want to"?

all of the same codes? it sounds like they are giving you the run around!!! what codes come back? there are so many need to have a good starting point of the codes that come back right away!!

Customer: replied 10 months ago.
These are his last words so far today by text:
"They are random pal... one minute it's clear the following they are back"
I suppose what really worries me is I will get the car back and it will not be fixed.. I really appreciate the long range effort Wolfgang ! I will try and see if they are specific codes, but this is what he has said. Hopefully talk to him later

ok !!

Wolfgang and other UK Car Specialists are ready to help you
Customer: replied 9 months ago.
Hi Wolfgang ,
Just wanted to give you a final update. It cost me £480 with the garage, and all the errors came back, and the misfire. I bought 6 coil packs to change the remaining ones. It I didn't need them in the end. Some of the soldering was duff on the lpg connections and maybe were damaged when removing the engine covers.
I have just had the air suspension overhauled(£50) with new rings etc and now only have back brake light error due to led upgrade by techart!
So I just wanted to say thanks for all the help!