After installing MS3Pro, noticed my speedometer isn't working. When I reach ~70mph, the speedometer starts to read ~35mph, same with Tuner Studio. I went and replaced the speed sensor and same issue. I don't remember if the problem persisted prior to me adding the below mentioned objects.

The only mods to the car

1. Soldered a VDO oil pressure gauge into the gauge cluster circuit board (flexible circuit that's attached to the back of the gauge cluster) so that I don't have to fish a wire for the sender.
2. MS3Pro
3. LSCoils

I would attest the problem to me screwing up the gauge cluster with my soldiering skills but would this also affect what the ecu reads (Tunerstudio)?

 

Note that the speedometer/tripmeter/odometer computer is in the cluster and it feeds the ecu. If you messed up the blue circuit with your skills then yes, your MS3 will be similarly afflicted.

 

I forgot to update but yup, you're correct. I swapped in a friend's cluster and it worked. gonna see how much another one will cost or see if I can put a jumper wire between the harness and where the speedo computer is.