ECMlink 2G ECMLink logging speed issue

[USMCGSX]

Hello, this is my first post, so please take it easy on the newbie.

I recently started using ecmlink and it feels like hitting a brick wall at 4500 rpm when i do a pull on my 2g.
After much fussing around with suspected fuel cut, clutch wires, and what not, I realized my ecmlink logs show 0 mph at all times. The rpm launch limit function is active even while in motion. Troubleshooting this while actually parked at 0 mph and not originally logging vehicle speed only made it more fun to figure out.

The VSS seems to be operating because my speedometer and tachometer are still working. I've never had any problems with my speedometer or cluster for that matter. So why does ecmlink only see 0 mph?

I do have an aftermarket digital speedometer that is connected to the pin that feeds the original gauge cluster.
I was under the impression that the vss pin 3 signal is split at j21 - yellow wire to the ecu pin 86; and yellow/white wire to the gauge cluster.

Does that suggest I have an open on the yellow wire going from J21 to ecu pin 86, or am I looking for a problem between J22 and DLC pin 14? Is pin 86 on the ecu an input or output?

I could check pin 14 on the DLC or pin 86 on the ecu, but what am I looking for, 5v? I don't have an oscope or anything to check for signals, just a multimeter to check for continuity or a voltage.

Planned on checking continuity between DLC p14 to ecu p86 for starters, but I'm not even sure if this is the right place to be focusing. Could it be something else causing this?


Appreciate any insight.

 

[steve]

Normally as you can see in the diagram the ECU provides a pull-up for +5v (just above where you clipped the picture). Make sure you aftermarket digital speedometer doesn't also provide a pull-up voltage.

The VSS grounds that voltage to generate the pulses.