Help! Car won't start after VAG COM

[userbob0001]

I just got a generic vag com, and I was playing with it. I changed my radio to have a cd changer, and logged some data on the way home. The locks and windows had been done a while ago. Then I changed my instrument cluster so that the washer fluid warning would work, and the seatbelt warning wouldnt. I got out of the car for a few hours, now it wont start. I changed the setting back, and that didn't fix anything. I also did a full scan, but it didnt give me any faults except that it couldn't talk to the hvac, but that shouldn't be a problem. I don't know what to do, and I have to go to work in the morning. Any ideas? what could cause this?

Edit: Forgot to mention. 99.5 1.8tqm

Edit2: Oh, yeah. I also did a throttle body adaptation. None of this seems like it should have bricked the car.

[BADB5A4]

Start from the top, were the lights left on during that time? Checked battery ?

What does it do when you turn the key?

If nothing else set everything you changed back to default values

[userbob0001]

The battery is fine. All of the electronics work fine, the car turns on just like it should. When I turn the key to start though, i get nothing. not even an attempt. I tried setting everything to default, but that didn't seem to have an effect. I know the american cars didn't have immobilizer, but is there anything like it that could be a problem? Do I need to recode for my key? I'm going to try jumping it today just in case that is the problem, but i want to say its reading something like 11.3 V. Which isnt too low to start.

[userbob0001]

Just in case, I tried jumping it. The voltage was low before that, but when I jumped it and tried to start it, it still didn't do anything except turn off the interior lights like it is supposed to.

[tdn]

does your check engine light come on with the key in the ON position?

[userbob0001]

Yes, but that is normal since the engine isn't running.. I turn the car on and all of the warnings test themselves, then airbag and abs go off, and i have check engine, brake, seatbelt, and something else, I forget what, but I think its normal. The instrument cluster doesn't change when I turn to start.

[tdn]

Did you check your ignition related fuses?

[userbob0001]

I checked everything in the main fuse panel. I don't know how to check relays. Did I miss any somewhere else? Are there relay's I need to check? how?

Edit: I found out that we have extra fuse slots in there too.

[Dallas09]

11.3 volts is really low batteries should always read above 12 volts, did you let the car charge for a sec while you jumped it before you tried to start it? The next thing id try is disconnecting the battery for a while and then trying again.

[userbob0001]

I've never had a batter read above 12 unless the car was on. Then its about 14. Anyway, My dad and I push started it last night and it started, so we charged it overnight, and it still wont start with the key. Going to check the battery to see if it is holding the charge that it is getting, and the starter voltage to see if it is the starter motor, or if something isn't letting the starter get power.

[userbob0001]

it worked fine when I bypassed the central locking system, so it is most likely within the anti theft system. Does anyone know what might lock someone out of starting the car.

[userbob0001]

Vag-com isnt detecting the position of the key, could this be an antitheft feature? could I have reprogrammed it to not recognize my key?

Edit: The key position sensor is for the door.

The central locking module won't ground the ignition signal so it can start.

[Dallas09]

I was told that North American audis didnt have anti-theft immobilizer keys until B6 models. I do know that the central locking module with prevent starting if the alarm has been activated but i dont think it will ever disable it for any other reason on a North American car. Have you tried arming and disarming the car and tried disconnecting the battery?

[Siena]

11,3V is low. Mine's normally above that with the engine not running, even after a week of not running.

Running should be approx. 14,4V with major current-drawing items switched off.

[mnsirtee]

11.3 volts is really low batteries should always read above 12 volts, did you let the car charge for a sec while you jumped it before you tried to start it? The next thing id try is disconnecting the battery for a while and then trying again.

^^ i agree, try disconnecting the battery over night. It might reset the codes done to the car. It deleted all my vag mods after overnight disconnected.

[userbob0001]

Well, the battery meter always said a little less than 12. I used a multimeter and it read almost 13 (after charging). Anyway, troubleshooting lead to the clutch switch, we took it out, pressed it, the car started. So we put it back and everything worked. She was just being a bitch. I thought it was the central locking because the clutch switch goes from central locking to ground, so I hadn't checked it, and i had also just been messing with the instrument cluster which is where euros have the immobilizer. So if your car mysteriously wont start after sitting for a couple of hours, check the clutch switch.

[Dallas09]

Glad you got it sorted out, i didnt realize the central locking dealt with the clutch switch.

[arankaspar1]

Bump, having similar issue. - - - 8EC - A4 08' 4DR AWD S-Line with Stasis ECU.


I was in the car about 3 hours tweaking what I thought was safe stuff. Some central locking and taillight dimming.
I was in 3 modules... Instruments, Cent.Elec. and Cent.Conv..

I only noticed the cluster lighting/DIS had turned off after modding taillight dimming percentage in Cent. Elec. Adaptation.

Now when I go to start the engine, CEL ABS and other cluster lights come one but DIS (Red Display) and needle LEDs don't come on.
Engine cranks but doesn't fire. Cranks for about 7 seconds and then coils click-click-click-click.
I couldn't get any modules to respond after the car being on more than 10 seconds so I timed my module click and ignition-ON, together. It then let me in. I reverted the things I changed and committed changes successfully.
Just before giving up for the night, I did a needle sweep test in the Instruments module and they all work fine. It got to the DIS test and nothing happened.
Also did a fault scan on the immobilizer and there was a fault 668 - voltage lower limit exceeded.
Pulled and re-seated all fuses in the drivers-side dash fuse box (need to check continuity and look closer in the day-time).
I locked the car and started going upstairs, the alarm sounded after about 5 min and it unlocked itself. Since then the remote locking hasn't worked.
This all happened last night and I then unplugged both battery terminals for about 10 min, with no luck.


1. Does anyone know if the Cent.Elec. and Cent.Conv. are in the same physical module?
2. Is this the BCM?
3. Do we know if the 17-Instruments "module" is actually within the cluster? :(
4. When voltage is low, could it cause only the cluster to stop working?
5. If a battery charge doesn't do it, should I replace the CentEelecCM or CentConvCM? Or do you think it's the Instrument module?
6. Is there another fuse-box other than the driver-side dashboard box? Is there one in the engine-bay or trunk that I couldn't find?

I would think the Germans would have prioritized the DIS power over things like say... HVAC, since it is responsible for a system module check.

Can anyone eliminate some things for me?
What is working... Climate Control, Headlights, Door-Switch Locking, Windows, Dome-light (delayed ON-response after pulling out key)
Not sure if this is still happening but on the first couple fire attempts the windows stop working about 30 sec after switching to ON, maybe voltage loss causes one of the module to give up?

Not working... Cluster backlight/DIS, Remote locking, Trunk lid release button

All signs kind of point to low battery voltage so far except I would image that the cluster would at least try to work before things like Windows and HVAC.
It is making a kind of faint rapid grinding/clicking noise in the middle of the dash.
As if a gauge were fighting itself to go both up and down at the same time or something.

I'm going to charge the battery tonight but I really need the car running so I'd just like to know your opinions on modules to replace so I can get them shipped asap.

Thanks a million!!

[RENOxDECEPTION]

9-year necro bump and on a b5 thread asking questions about a b7, best to make your own thread in the b7 section.