audi a4 cabriolet remote top operation
Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=117544
Printed Date: July 03, 2025 at 8:30 AM
Topic: audi a4 cabriolet remote top operation
Posted By: tcool
Subject: audi a4 cabriolet remote top operation
Date Posted: November 07, 2009 at 1:23 PM
I am installing a compustar pro alarm/remote start in a 2003 audi a4 cabriolet. I am trying to hook up the convertible top to the alarm so I can remotely open and close it with the auxiliary channels. The interior switch seems to be controlled by the bus system, and is not easily hardwired. The motor is operated by a controller, and doesn't look like something I could safely wire a DEI 529t with. I'm sure it can be done because the smarttop controller by mods4cars can operate it via the factory remote. Anyone ever do this, or have any ideas.
Thanks!
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Replies:
Posted By: metz35
Date Posted: November 07, 2009 at 3:46 PM
no way to do it...its can bus all the way, could try to find the actual motor wires to the top but you still wouldnt have the windows crack when the tops going down so i would not recommended it
Posted By: howie ll
Date Posted: November 07, 2009 at 4:19 PM
I know on earlier pre-CAN versions, say up to 2001, you could simply extend the lock pulse as in the 3 series BMW. Effectively you have to power up the ignition and then possibly feed the switch.
Posted By: howie ll
Date Posted: November 07, 2009 at 4:42 PM
Sorry to post again on this subject but I was just looking this up on Autodata (do you have it in the US?). It lists roof open and close relays behind the trim, right hand rear in the trunk. No actual wiring, just component positions. You could do it across both relay motor outputs because that way it emulates a switch using a 529t. Just go to the trunk and find the two motor wires.
Posted By: chriswallace187
Date Posted: November 08, 2009 at 12:47 AM
Wouldn't there be a latch at the windshield that you'd have to deal with, in addition to the power top motor wires? Or does applying power to the motor wires release that as well?
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Posted By: howie ll
Date Posted: November 08, 2009 at 2:03 AM
Not sure, I think it's like Porsches and later, about 97 on 3 Series, no mechanical latch. Wish I could see a wiring diagramme, might be a way to "spoof " the processor that controls it.
Posted By: tcool
Date Posted: November 08, 2009 at 2:35 AM
Thanks for the replies!
The top is fully automatic so there are no manual window latches. I think that I might just be able to power the relays with a timed output, but I'm not sure. I think that there might be different mechanisms for the boot lid and the top (maybe even the automatic windshield catches). There are quite a few wires, so I am going to get a helper to operate the top while I check the wires. Of course some of them are in the trunk, which has to be closed for the top to operate. And, of course, Metz has a good point that the windows wouldn't roll down before operation as required.
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Posted By: howie ll
Date Posted: November 08, 2009 at 10:36 AM
Frankly unless you can obtain a circuit diagramme let alone follow it (no insult intended) the method you're going to use is the only way. I suggest a collection of 528ts or similar. You need a control that brings on window drop prior to roof close. The trouble is the factory could do this via the closing relay or earlier in the chain via the processor. we just don't know.
Posted By: 91stt
Date Posted: November 08, 2009 at 11:57 AM
I have a pdf wiring diagram that should help but i can't attach it
shoot me a pm with you email address and i'll send it over
Posted By: 91stt
Date Posted: November 08, 2009 at 12:26 PM
scratch that, i uploaded it to the downloads section
https://www.the12volt.com/installbay/downloads.asp?srch=all&term=audi+a4
Posted By: howie ll
Date Posted: November 08, 2009 at 1:00 PM
Thanks 91, looks like we are looking at yellow/red and yellow /black from the module, see what they do. I bet they each go to ground to change the roof direction. I didn't look to see if there was an ignition feed to that module, you might also want to make that live via 87a of a relay for a few secs then maybe ground the close side of the roof switch. also wonder if giving a live feed to the grey/blue at the switch would help.
Posted By: tcool
Date Posted: November 08, 2009 at 1:20 PM
Thanks 91stt, that's perfect. At least now I know what I'm up against. Too many moving parts for going straight from the motors or relays, not to mention windows (for me, anyway). I'm going to try to see if I can work anything from the door key switch (a double pulse and hold also operates the top- so maybe a PAC TR7 would work there). Worst case scenario I can buy the smarttop controller and hardwire the compustar to a key remote.
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Posted By: howie ll
Date Posted: November 08, 2009 at 2:17 PM
Don't want to sound stupid but have you actually tried setting your unit for double pulse lock and some kind of comfort control, either through the locking system or as an aux?
Posted By: tcool
Date Posted: November 08, 2009 at 6:21 PM
No howie, I haven't. The ADS blade plugs into the back of the alarm and handles the transponder and bus system, which includes the locks. There is no option to have the blade do comfort control, but I'm going to try and go into the door and hardwire it from the door control module. I planned on doing that anyway for window rollups, so maybe it will control the top, too.
I really appreciate all the input you guys are providing. After I took of the panel and saw all of the wires going into the control module and motors, I was ready to give up.
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