Had my trans flushed at the dealership today. Apparently after they finished and did a test drive, it threw a code P1721 for "VEHICLE SPEED SENSOR MTR". They're doing additional diags on it free of charge, as they didn't want to just wipe the code and send me on my way. The tech said it was shifting fine. The service advisor said she wanted to have her master tech take a look and see what he could find before they gave it back.

I can't find any info on this code, other than what it stands for. Anyone have experience with this one?

Silver lining; my loaner is '12 G37x

 

Dealership still not sure the source of the issue / how to fix. Tech drove it again Friday and it threw the code (after not doing it Thursday). He noticed that when letting off the gas, the speedo would drop to around 10mph for a few second, then go back to whatever your actual speed is.

Service advisor said they wouldn't have more tech time till Tuesday, and they also want to contact their "tech line" about getting additional information about the issue.

So, still slumming it in the loaner...which I'm noticing sucks up gas a shade quicker than mine does.

 

Did they do a flush or drain and fill??

 

They didn't want to do a *full* flush, due to the mileage (106k). So just a drain and fill.

 

Oh I was about to say...flush is always a bad idea

 

did you figure out ur problem

 

Yes, problem resolved itself when I sold the car.

 

That code means the instrument cluster is not spending vehicle speed data to the TCM (or it's not being received by the TCM due to faulty wiring).

Does anything on your instrument cluster not work properly? If so it's probably the instrument cluster.

You can put the AT system into diagnostic mode to run a self-check. FSM section AT - Automatic Transmission under the header Trouble Diagnosis - Diagnostic Procedure Without Consult II

https://www.nicoclub.com/infiniti-service-manuals