I have a 96 A4 2.8L 20V with a 5spd tranny. A few weeks ago, I started to pull out from a gas station into traffic and the car stopped running. It stopped hard, like I had hit something, and then it stopped turning over. It would cranks, but not fire up. I pulled codes and only got one for the engine speed sensor. I replaced it, cleared the code and tried again, it turned over once or twice, but then went back into cranking, no spark. Again the Engine speed sensor code popped up. I returned the sensor thinking it was faulty and tried again. Same result. This time I cut off the fuel to check something, I cranked it, and of course no start, but no code either. then I got the fuel running again, it cranked and turned over 1 or 2 like it was just going to fire up, and then the code pops up and no spark again. So now I know something is causing the sensors to go out. What could that be? The only code is the one for the engine speed sensor. But I have burned up two sensors, and gotten no results. Thanks in advance for any help!

 

Have you tested the sensors with a volt/ohm meter to make sure they are bad?

if your engine speed sensor is bad, the car will not allow itself to start,And if the signal fails while the engine is running and you're driving it, it will cause the engine to shut down immediately (what you are describing).

Also, I believe (haven't looked at a diagram in a long time) that the engine speed sensor needs to be working for the fuel pump to engage...could be wrong though...

We are talking about the CPS (Crank position sensor) correct? Tell me where the sensor is located that you switched out and what is your exact code you are getting?

 

The sensor I've replaced is on the side of the block, just behind the oil filter, I can reach it from in front of the driver's side tire, takes 5 minutes to exchange, Held in by a 10 mm bolt.
The code information is :
Control Module Part Number: 8D0 906 266 B
Component and/or Version: 2,8l V6/2V MPI OBD2 D01
Software Coding: 01001
Work Shop Code: WSC 06317
VCID: 2B2984AFCA0B
1 Fault Found:
16706 - Engine Speed Sensor (G28): No Signal
P0322 - 92-00 - Unknown Error Elaboration

Is there a post here that would show me the process for testing the sensor with an ohm meter?

 

Unless the 12valve v6 is much different from the 30valve, it doesn't sound like you've replaced the correct sensor. The symptoms you describe and subsiquent code are consistent with CPS failure, but the sensor location does not. The CPS on the 30v and 40v engines is actually mounted to the transmission bellhousing. Take a look at the driver's side of the trans, just behind the block.

 

That's why I asked what sensor you are replacing, the CPS sensor should be on the tranny bell housing on the 30v....so I believe you are replacing the wrong sensor.....that's why the code keeps coming back.

 

I have the 12V, not the 30V unfortunately. Can't find a lot of info for the 12V.

 

It's in the same area as the 30V from what I know. Attached picture.

The speed sensor should be mounted on edge of the bell housing of the transmission above the teeth of the flywheel....

 

Just an update. I know this has been a while but I got it sorted out. There are 2 sensors, they use the exact same part for both. One is the one I was looking at, and the other is about 4-6 inches from that sensor, toward the back of the block, and an inch or so higher. Just as easily replaced, but I couldn't see it. I actually put the old sensor from the other location in, and the car started right up.

 

GREAT NEWS! And thanks for posting the solution!