The only "sensor" or "switch" I see on the EPC and diagrams is just the reverse light switch. Wondering if maybe this is a donor for a different car that had TCS? I don't believe there is an input for gear selection. The only speed wiring on this 94 CDE is wheel hub and it's specifically tied to the ABS computer.
It the speed transducer that sends the signal to the speedometer. If you remove both pieces there. You will find it has a small plastic gear on it that meshes with the plastic gear on the differential. If you look at a parts blow up of the case were it shows the back up light switch the bottem part of it is shown as part 23 and 25. If you unplug the elctrical connector and drive it you won't have a speedometer.
I see the connector information on the 1994 service book. It's not in the other book, it shows a cable. I'll have to dig and figure out what happened. I would expect both connectors to be mated still LOL.
I think from 1985 to 1994 the speedometer got its data from a cable arrangement, and 1994-98 used an electronic sender, so if yours is a 1994 and you are still getting speedometer readings this sensor only sends a signal to the ECU. T5 needs to know what gear you are in and I think gets it from here.
The speedo cable was discontinued in like '88 or maybe '89. After that was a VR (IIRC) sensor on the final drive that ran directly to the speedometer... The sensor pictured is that sensor. It outputs sine, and then the speedometer converts that to a 4000ppm square wave, used by LH and by Trionic. I don't think 9000s were ever "adapted" to use the ABS sensor like the NG900. The speedo sensor connects directly to the speedometer, nothing in the middle. I use the same sensor on my T5 c900, and use a Speedhut speedometer to convert to 4000ppm square.