NefMoto

Hi everyone,

I am a newbie and before I dive head on with all this - I wanted to see if anyone can direct me or help me in coding out this P0501 vehicle speed sensors on my 2002 Audi TT Roadster AMU - I have replaced everything, rebuilt the cluster, changed more than 6 sensors, traced all wiring etc. SInce it is an intermittent error - it was suggested that it maybe a lose contact- wire somewhere in the car. It is relatively impossible to find...

I want the CEL off. I understand that there is a way to code-out that specific DTC from the ECU.
I will pay for time to guide me thru the process. Massimo.
 

Upload the orig file

Probably 018AN if it's NA.

IMO coding that one out is not a good idea. You really need to fix the root cause, or you will have other issues, unfortunately :(

Why? I know that that sensor interacts with many components: cruise control, comfort module, breaks, radio and ECU...you don't think that if I am able to just "turn-off" that specific code - the rest of the software would be able to work?

Unfortunately, you may experience odd issues in all of the above if the sensor (and hence its readings)  is faulty and you just disable the DTC.

Disabling the DTC just turns off notification of the fault. Nothing else.

It is like disconnecting your smoke alarm and expecting it makes your house fireproof :)

But indeed, I would like to turn off the "notification" of that specific code. The car runs fine. I am just tired to look at that MIL at night! I was able to pass inspection in NY by doing the VAG-COM cycle and readiness outside the station...

 Please let me know if you can guide me in how to turn it off. At least I can try and test to see if it affects other stuff. Need guidance in how to do it. Massimo.

There is a sticky on this forum that will tell you how to do it. I offered to help before. if you could upload the original file or at the very least tell us the software version i can tell you an address.

Thanks i will work on downloading the file.

It would really be better to find the map that is causing the dtc.. the error still exists in the system, it just isn't being reported to VCDS (or setting a the MIL)

If you are convinced the speed sensor is fine, you need to loosen the error detection parameters, not mask the DTC.

One more time MASKING THE DTC IS ALMOST NEVER THE RIGHT ANSWER.

if the hardware is bad, you need to fix the hardware.

if the hardware is NOT bad, you need to loosen the parameters (usually in a map somewhere) that are causing the ECU to detect the error, not mask the error.

Consult the FR to find the appropriate map(s) that need to be modified.

The previous owner confirmed that he did not flash the ECU. However, the engine was replaced (hit by object at high speed on highway) could it be that Audi "double-flashed" the ECU?

When I used the ME7Check (from the NefMoto forum) to check the BIN:
 
me7check v1.12 (c) mki, 06/2004-05/2012
Checking file 8N0906018AN 0004.Bin (size=1048576)
Reading Version Strings...
-> Bootrom Version = embedded in CPU, asume 05.12/05.32
-> EPK = 40/1/ME7.5/5/4018.00//22I/Dst04o/280501//
-> Contents of ECUID data table:
   - '0261207418'         (SSECUHN)
   - '1037362588'         (SSECUSN)
   - '8N0906018AN '       (VAG part number)
   - '0004'               (VAG sw number)
   - '1.8L R4/5VT     '   (engine id)
 
WARNING: flash should be 512kB of size, but the file is 1MB !!
-> trying to analyze only the first 512kB of the file
 
-> No errors found. File is OK.   *********************

It seems that the program was "expecting" a 512K file instead of a 1MB? Why?

Question: 1) if BIN is flashed and/or corrupted should I flash an original BIN?
2) Could it be the issue?

Have you checked and cleaned all your engine bay earths? The little ones and the big earth strap to body and engine.

Had this on a Mk1 Leon diesel before over certain speed for some reason speed sensor cut out.

Cleaned all earths to metal and happy days it was fixed