Ok I'm new to the Audi world, just bought my first one; an 04 A6 Quattro 3.0L. I bought it not running (I know, bad Idea) but I spoke to the tech at a dealer who diagnosed it as a bad fuel pump before I bought it, so I bought it anyway as an easy fix. Well, turns out he's a moron and after some testing, there is no voltage to the pump. There is no voltage to the fuse. If I cross pin 30 and 87 in the relay, the pump will run but the car still will not fire. It pulls a p0600 code,ECU not communicating with computer but that is the only code. I was told the car died immediately after hitting a pheasant on the road if that means anything.. Anyone have any ideas? I've heard things about a wet ECU and the ABS module causing such symptoms, where are they? Thanks in advance

 

TTT really, nobody?

 

Somebody's gotta know where the ECU is!

 

It's under the wiper cowl by the windshield, I believe the drivers side area bottom of the windshield. Access it by opening the hood. That P0600 code sounds like the cable is not plugged in but that would only happen if the cpu was by the oil pan where this pheasant got run over. I'd look around that area for any wiring that is damaged or unplugged.

It's not the abs module, which is attached to the abs pump and located under the hood, drivers side on top of the inner fender area. My friend unplugged the connector to that module and his car drove fine so that's not it either. ABS light of course was on when he did that but it was already on.

I suppose it could be a wet ecu though, if that cover on top of it is damaged or not there it might get moist inside the compartment where the ecu resides.

 

I believe I've located the ECU under the driver's side wiper cowl. I pulled the plugs and they're bone dry and clean as a whistle like they just were new yesterday. What's next in line, can someone test the ECU?

 

I don't work on these cars, so I don't know the placement of wiring or cables. You jumped 30 (battery power) to 87 (load, fuel pump) and the pump runs. That means the trigger terminals that are part of that relay aren't getting a signal to tell it to activate. If they did then your pump would run assuming the relay is not bad.

So you jumped it, pump ran, engine spins but doesn't fire. My first guess is that bird damaged a sensor or wiring to a sensor like an RPM or TDC reference sensor. This sensor tells the ecu that the engine is turning over or running. If that cpu or fuel pump relay doesn't know the engine is turning over it will never tell the fuel pump to activate.

So your 2 problems could be related to one repair, if it's something like I described above, wiring under the car damaged. Did you look under the car yet for any obvious signs of wiring problems?