03 RS6 Will Not Start

Hello,
I need some help. My RS6 has been parked for about 2 years. My alternator died right at around 70k miles (timing belt time) and I procrastinated because I did the 35k service and didn’t enjoy it. So now I’m motivated to get her going again, put in a fresh battery and turn the key and nothing. Everything electrical seems to work but the starter doesn’t even engage, or click. It’s not the immobilizer, the key is fine and that light goes off. I’m thinking I may have caused this, at one point I had to move the car and just shifted it to neutral to push it out of the way without the key in the ignition. Could I have damaged the auto transmission range switch or maybe the ignition interlock cable? If it’s not that is there a relay that could be the culprit? I’d appreciate any insight or experience anyone may have had with similar problems. There are no codes that that would seem connected to this problem.
Thanks

The bad news is it could be a lot of things. Helpful if you can trace wiring. For a start I have included the picture of the relays in the lower left side of the steering wheel and you can start with the Starter Interlock relay. The Good news if you think the timing belt is bad on an RS6 (it definitely was back in the day), many newer performance cars are much worse to work on.
Attachment 19620

Can you scan the RS with VCDS?

Hahnmgh63
Thanks for the relay diagram, I will check that out. I can only imagine how much more complicated and convoluted high-end cars have become since 2003.


Kilian Tuning:
I did a VCDS scan and there was nothing that looked like it would keep it from turning over. I’ll readily admit to only having a basic user level of VCDS use.

You didn't specifically call it out, but the 'foot on brake' light in the dash does go out when you put your foot on the brake to start it right? That switch (tied to the brake pedal) can go bad and will prevent the starter from engaging.

Quote:

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Originally Posted by JakeLight

You didn't specifically call it out, but the 'foot on brake' light in the dash does go out when you put your foot on the brake to start it right? That switch (tied to the brake pedal) can go bad and will prevent the starter from engaging.

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The light does go out but hadn’t considered that switch. I’ll test it out, thanks!

I really wish that I had documented it but there is a really easy way to bypass everything to crank the engine

There is a 2 pin connector on the firewall that goes directly to the starter solenoid. Just turn the key to the on position and unplug and jumper the correct pin to a 12v source and the starter will run.

If it does, then you still need to figure out what the problem is upstream from this connection.

I am having the same issue, started the other day not starting once or twice now no starter engagement at all. I haven't started looking into yet but if I find something relevant I will update you here in this thread.

Thanks to everyone for their help and suggestions. The problem turned out to be the transmission range position switch. I probably caused the issue by shifting it to neutral without putting my foot on the brake. My mechanic was able to remove and install the new part without removing the header as called for in the service procedures. She’s back on the road and running great. Reminds me why I still love this car.