[s-cars] Avoiding autocheck "alarm" on C4 chassis car

[Sean Douglas]

The relays will cause a lamp out because the resistance is different and the
Autocheck lamp control module (LCM) monitors the resistance and if it see
something different it causes the bulb out symbol. The LCM monitors the rear
brake lights and rear tail-lights too, so I did not want to disable it
totally. So, in a nutshell, I bypassed the portion of the LCM that sees the
voltage/resistance for the low beams.

The LCM is located in the relay box under the hood by the driver's firewall.
It's the double relay marked 387. Remove this relay and what you need to do
is pull up on the mount to get access to the wires below. Removing a couple
of other relays around it will help. Locate 4 wires, which are marked on the
holder, 56br1 (yellow), 56bl1 (yellow/black), 58br (yellow/brown), 58bl
(yellow/green). Cut the wires as close to the connector to give you some
slack. Use an insulated butt connector and connect 56br1 to 58br and 56bl1
to 58bl. Its tight to get your tools in here, but doable. You have now
bypassed the LCM for the low beam (xenon) and the bulb out will not come on
- ever. See attached wiring diagram.

The downside is if one of your low beam bulbs burn out, the auto-check
feature will not work.

Sean

> -----Original Message-----
> From: s-car-list-bounces at audifans.com 
> [mailto:s-car-list-bounces at audifans.com] On Behalf Of Eyvind 
> E. Spangen
> Sent: November 13, 2007 6:07 AM
> To: 'quattro'
> Cc: s-car-list at audifans.com
> Subject: [s-cars] Avoiding autocheck "alarm" on C4 chassis car
> 
> I relayed the headlights on my dad's '92 100. After doing 
> this, the autocheck will complain about a bulb not working.. 
> The autocheck front bulb control module sits in the underhood 
> relay/fuse box, so it's easy to access.
> 
> The problem is: How do I fool the autocheck and get rid of 
> the warning?
> Doing like on the type 44 autocheck system will *not* work. 
> Disconnecting the signal wire from the bulb control module to 
> the instrument panel will not work either. No matter what I 
> do, it will light up. Anybody BTDT?
> 
> --
> E. Spangen
> 
> 
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> Date: 12.11.2007
> 21:19
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