Coyote PCM VSS input?

tcollins · Aug 1, 2017

I have scheduled the chassis dyno to get my engine calibrated. My shop told me that I need to add a speedo recalibration device before I bring them the car. They gave me the Ford part number M-4209-ADPT-A. I didn't see anything about this in the Controls Pack info, so I called Ford Racing. They told me that I don't need this to do calibration for my configuration; 2011-14 Coyote crate motor, with M-6017-A504 Control Pack and Tremec TKO500 trans.

I was wondering if anyone else has added this device?

I see that I can buy it at Summit ($150) and it seems relatively straight forward to add into the PCM harness, but just wondered what would happen if i simply connected the VSS speedo signal from the trans into pin 14 of the ECU? I can understand that it might be slightly off due my wheel tire size but I don't understand why the engine controlled needs this input?

edwardb · Aug 1, 2017

I did quite a bit of research on this topic before starting my Coyote Roadster build. As it turned out, I used the 2015+ Gen 2 version Coyote and the speed dial module is definitely not required. Was told that by Ford Racing right after I bought it, and can confirm with now 1000+ miles on the installation.

Two response to your questions though, based on the research I did but not actual experience. (1) No, you can't use the output from your transmission speed sensor directly. (2) Many reports that the speed dial module is not required in later versions of the 2011-2014 PCM. Apparently Ford made a program change that solved the stalling issue. But this would be something to confirm directly from Ford Racing. Suspect this is what they meant when they told you it wasn't required. But I would confirm the reason. Hopefully they didn't misunderstand and think you were running a 2015+ Controls Pack.

Coyote PCM VSS input?

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