# Replaced HU, now VW Service won't use their Diagnostic Tool



## fkestrel (Nov 17, 2001)

Hey all.
2001 NB Sport here. Installed Blaupunkt Heidelberg CD51 - love it. VW Service will not test my vehicle with their computerized diagnostic tool, until I remove my HU and reinstall the original. Is this for real? Its a major pain in the butt. I would think there has to be a way to reprogram either the CPU or the tool to make up for the missing radio which apparently completes their testing circuit.
Anyone come up with a solution to this issue?


----------



## Charles R (Oct 26, 2001)

*Re: Replaced HU, now VW Service won't use their Diagnostic Tool (fkestrel)*

The reason for this attitude is a wiring snafu. It seems that the the wire that comunicates with the VAG 1551, may be wired to a 12volt source. This happened with many store bought adapters. Ross-tech even has an info page on the problem.
The reason the dealers are so frightened of it, is that the VAG 1551 does not have a fuse (like the VAG-COM) to protect the scanner from the voltage spike. Plug in the scanner, POOF, dead scanner. Big repair bill. The irony of this, your car is unaffected by the miswire. It just kills dealer equipment.


----------



## g0dl355 (Jul 18, 2001)

*Re: Replaced HU, now VW Service won't use their Diagnostic Tool (Charles R)*

thats bs
just take a polaroid of your taped off k-wire..
they told me the same bs...
and i told em to where they could stick their vag tool


----------



## Dave 53105 (Oct 2, 2001)

*Re: Replaced HU, now VW Service won't use their Diagnostic Tool (W0lfsburg4)*

There's a TSB on this, #C91-99-01 dated Feb. 5, 1999. Just tell them your installation complies with this (assuming the K-wire is actually not connected to your HU) and you should be fine.


----------



## Guvs97JettaGT (Sep 27, 2001)

*Re: Replaced HU, now VW Service won't use their Diagnostic Tool (Dave 53105)*

Well, this is funny, cause as far as I know Blaupunkt is by Bosch and Bosch is owned by VW. So, if their own product doesnt comply, thats funny.


----------



## fkestrel (Nov 17, 2001)

*Re: Replaced HU, now VW Service won't use their Diagnostic Tool (fkestrel)*

Thanks for all your comments. I think I will go ahead and do the photo of my wiring. That will at least proove I can't blow up their tool. As for whether or not they can still test away with the "factory hu" completing its curcuit is still up for questioning. Unless the service advisor was just full of crap.


----------



## Nason (Feb 17, 2001)

*Re: Replaced HU, now VW Service won't use their Diagnostic Tool (fkestrel)*

The biggest problem for the dealers is that the VAG 1551 is very quick and easy to use, and costs 10% of the VAG 5051. VW wants dealers to phase out the 1551 and go straight to the 5051, so all parts support for 1551 components has ceased, but software updates are available. If a dealer spikes his VAG 1551, he's [email protected]#*&%.


----------



## F1_Fan (Apr 16, 2001)

*Re: Replaced HU, now VW Service won't use their Diagnostic Tool (fkestrel)*

quote:[HR][/HR]Thanks for all your comments. I think I will go ahead and do the photo of my wiring. [HR][/HR]​Good idea. 
If I ever go aftermarket HU I'm gonna get the dealer to snip the k-wire during a service. Then if there's any question I'll just show 'em their own workorder with the k-wire snip.


----------



## nicko (Jul 29, 2000)

*Re: Replaced HU, now VW Service won't use their Diagnostic Tool (F1_Fan)*

I just installed the Blau Heid. CD51 in my GTi. My questions is which wire is the k-wire.. any pics please??? Also how is your reception?? Did you us the antenna adaptor.
Thanks,
-- nick


[Modified by nicko, 1:37 PM 11-27-2001]


----------



## nuke (Sep 19, 2001)

*Re: Replaced HU, now VW Service won't use their Diagnostic Tool (nicko)*

Pull the radio, have the dealer verify that your K-wire is correctly isolated and NOTE it in writing in your warranty booklet.


----------



## vw2.0gti (Nov 15, 2000)

*Re: Replaced HU, now VW Service won't use their Diagnostic Tool (nuke)*

bump


----------



## MADBUG (Dec 14, 2000)

*Re: Replaced HU, now VW Service won't use their Diagnostic Tool (fkestrel)*

quote:[HR][/HR]Thanks for all your comments. I think I will go ahead and do the photo of my wiring. That will at least proove I can't blow up their tool. As for whether or not they can still test away with the "factory hu" completing its curcuit is still up for questioning. Unless the service advisor was just full of crap.[HR][/HR]​The factory hu does not have to be in place at all for the VAG to operate.If the dealer still gives you crap after taking a pic of the disconnected k-wire,then just pull the Blau out.


----------



## NewbieBaby (Nov 29, 2001)

*Re: Replaced HU, now VW Service won't use their Diagnostic Tool (MADBUG)*

Concerning treatment of the "K" wire, refer to this site: http://www.springbreakdaytonabeach.com/vwtech/www.vwwebsource.com/vwtechcontent/ 
There is Technical Bulletin 99-01 which has information about specifically which lead on the conector is the K wire and what to do with it. Copy the bulletin and show it to the dealer along with any other documentation.


----------



## fkestrel (Nov 17, 2001)

*Re: Replaced HU, now VW Service won't use their Diagnostic Tool (NewbieBaby)*

Thanks for the reply NewbieBaby! The TSB 91-99-01 was just the ticket! I'm including a picture of the actual location of the mysterious K Wire for everyone else. Apparently its the same on 97 and newer Golf, Jetta and Beetles


----------



## jeanmp3 (Dec 4, 2001)

*Re: Replaced HU, now VW Service won't use their Diagnostic Tool (fkestrel)*

Well.... I think I have a slightly different problem. When I removed the factory HU of my 2002 Passat (a double DIN cd/cassette model)...the VW service analyser was unable to talk to the Passat computer. Seems like the factory HU completes the circuit so the tester will work. 
Anyone know what I can do other than hook up my factory HU everytime I bring the car in for service? I am not sure that the K wire has any bearing on this problem.
Thanks!


[Modified by jeanmp3, 6:10 AM 12-5-2001]


----------



## UKAUSSI (Oct 21, 2001)

*Re: Replaced HU, now VW Service won't use their Diagnostic Tool (jeanmp3)*

quote:[HR][/HR]Well.... I think I have a slightly different problem. When a removed the factory HU of my 2002 Passat (a double DIN cd/cassette model)...the VW service analyser was unable to talk to the Passat computer. Seems like the factory HU completes the circuit so the tester will work. 
Anyone know what I can do other than hook up my factory HU everytime I bring the car in for service? I am not sure that the K wire has any bearing on this problem.
Thanks![HR][/HR]​Check out this thread for some info on the 2002
http://forums.vwvortex.com/zerothread?id=167793


----------

