jtr8

Looking for the location and possibly any known writeup to locate and change the Crank Position aka Engine Speed Sensor (I believe they are the same thing) for my B6 A4 3.0.

EPC and CEL, takes 3-5 seconds to start, idles around 1200. VAG >> Engine Speed Sensor (trying to get a hold of saved scan file).

Ordered the Sensor, now just need to find out where it's located and what might need to be done to gain access to the location.

Thanks!

SlvrAvnt30

The crank position sensor is located at the back of the motor on the drivers side on top of the tranny behind a small heat shield. Move the coolant resovoir and you should see the small sheild down in the back of the motor. If you dont see it follow the wire from the beige plug on the fire wall on the drivers side. I was able to bend the shield out the way to get to the sensor.

jtr8

Thanks for the information. Were you able to get to the sensor from the top, or did you have to go from under? I removed the coolant tank, followed the top end of the sensor (that routed to ECU), removed the heat shield that was encasing the wire, and ran into a dead end. Basically, I couldn't get my hand down far enough to follow the wire to its end point.

Do you know if it's located in the same general area as the 1.8T (near the oil filter)?

Thanks for the help.

CalSam

JTR, any update to this to see if you ever fixed this? I'm in the same boat as you right now.

300kqtr

I just did this last month. It's fairly easy to replace. It's located exactly as described above. I will just add that the small heat shield is bolted in with the sensor and obstructs the view from underneath. If you feel around it's fairly easy to locate the bolt and loosen with an Allen key. The only other thing I would add is that the wire runs through a heat shield with the rest of the wires going to the back driver's side of the engine (i.e. O2 sensor wires... etc.) this shield is actually fairly simple to open as it has two snaps. Again, it's not really one that is easy to see, but if you feel around, it's pretty simple to open and close the snaps once they are located.

kaelan

was in to this problem myself and took me and a friend a while to find it on my 2005 a4 3.0 quattro with MT ( i believed having the MT slightly moves the sensor from the videos of auto's i was seeing) we took a video ill post that here: hope it helps you find it easier than I did lol! (wasnt the easiest thing to video is our situation but did our best

turbo510

I have an '05 3.0 automatic, and changed that sensor a few years ago. But it didn't solve my occasional long starts, high idle, and that sensor code. It turned out that my ECU relay, which is actually two sets of contacts in one housing, was the problem. I determined this, by chance, when driving over a road reflector dot, which caused a momentary power dropout, followed by the high idle. Re-starting would restore driveability, but nevertheless I removed the relays from the ECU box, and proceeded to open and check the contacts. The ECU relay has one large set of contacts, which seemed OK. A second, smaller set were barely making contact when the coil was powered, even needing a finger push to work. Re-flexing the brass arm and polishing the contacts fully restored it. The power dropout was evidently causing the engine speed sensor code, without the speed sensor actually being the problem.

Don Copeland

Are you referring to the relays under the engine ecu and trans ecu under the hood by the dash? If so which relay. If not can you shed some light on the location of the relay you corrected?