Shark_V8

Just turn the key quickly - a) the gauges back-light and warning lights all come on -check? You should hear a bank of 4 or 5? relays pulling in if you have a good ear.
b) your center console illuminates and you can run the audio system/MMI - check?

Finally - What is your outside temperature?

PS: If you hook up your voltage meter to the battery, then try to start, you'll get an idea of the battery's ability to provide current. For example I had a bad battery that held 12.6 unloaded, turn to start it went down to like 4 volts!

About the rear "dome" lights - Come to think of it I did have funky operation of my rear lights too. I haven't since I replaced my faulty right rear door control module. Anyway those little dome bulbs would take days to drain the big capacity A8 battery.

MP4.2+6.0

WAG: something wrong with ignition interlock. Try moving gear shifter in and out of Park, starting in Neutral etc. Try stabbing brake pedal hard before pushing on it. Also maybe brake pedal sensor is shot? Known issue in D3's, especially early ones.

Other/independent idea: Just disconnect battery. Leave it disconnected at least 30 min. Then reconnect and see what happens. Sometimes you can get to where it just needs a complete car reset. Not really understood exactly when or why, but the battery disconnect can clear some odd symptoms as long as the battery itself is good.

astrorat

I turned the key quickly and the center console lights came on and the MMI was operating. I did NOT hear any relays.

My wife turned the key while I held a volt meter on the battery. There was no significant change in the voltage (it dropped from 12.5 V to around 12.3 V).

The temperature outside last night was in the upper 50s and this morning when I tried again it was also in the upper 50s.

The headlights will not come on (except for a tiny light on each side), but the HID do not ignite. If I try to turn on the high beams by pushing the left stem on the console forward, nothing happens. If I pull back on the same stem, the high beams will come on for as long as I hold the stem back.

astrorat

I am not able to move the gear shifter out of park. When I try, I hear some clicking (relays?), but the gear shift won't move. I tried pushing hard on the break pedal and that had no effect. My wife tells me that she routinely starts the car without her foot on the break pedal.

I will try disconnecting and reconnecting the battery later. Should I attached a battery tender to the positive and negative leads to not loose the computer settings? Or is the intent to "reset" everything? An earlier post stated that there may need to be a reset if the battery is disconnected (and others stated a reset was not required).

MP4.2+6.0

BINGO: another sign it is the brake switch if you can't move shifter. Car start should also only be with foot on brake, so I don't understand that history your wife reports either--unless also broken for that or hacked around or something. All U.S. D3's would have this (and presumably Canada), but I think it is worldwide now on Audis, and has been a long time. Switch is cheap, but you have to pull down lower inst. panel trim to get at it. See prior posts if you search. I would work this angle. Known failure point, especially on early ones like yours where it is a question of "when" not "if."

Yes, if you disconnect battery for that idea, do NOT then back feed some power tender thing. The only thing you lose is the clock/date (easily reset in MMI) so no big deal. You also cycle the windows once full down, then full up with finger holding each switch to restore the one touch down/up feature. That's it. Rest of settings like radio and so on should all still be there.

Shark_V8

I had to jump in the 04' A8 to bring a box to the PO so here's what I did:


- Insert key, steering lock drops, MMI pops and I hear Drizzy (You the best I ever had
- Turn key quickly, ignition ON, but not start , cluster lights up etc. and yes the faint clicking as the relays pull in - passenger footwell.
- Ignition on, engine not running, I can step on the brake and move the gear lever, not a problem. There is a switch to sense park for sure.
- Feet OFF the brake (NO pedal), turn ignition off, then back to start, car fires right up.

So no need to press the brake... or clutch

astrorat

Thanks. I will go an get a new brake switch and replace it. My wife may be misremembering what she does out of habit when she starts the car. Even the owner's manual states the brake pedal needs to be depressed when starting (I know ... when all else fails ... read the manual!).

Shark_V8

I didn't remember that '05 you have the start/stop on the console.
Brake pedal to activate engine start/stop is standard fare for any car with a button.

For us that is the Focus and RAM truck.

astrorat

Picked up the brake switch ... now removing the lower trim panel beneath the steering column is a royal pain! I removed the three T-25 screws (two on the fuse panel on the side and one underneath near the right side of the foot well), but the dang thing does not want to come off!

astrorat

Whoops! I found two additional T-25 screws behind the trip pieces on either side of the steering wheel. The video I found online was for a different model Audi and I thought it would have been the same.