Vehicle Speed Sensor Malfunction P0500

[FlipIt]

I reinstalled the cruise control module and went for a short (5 mile) test drive. The cruise control worked fine at 35 mph and 45 mph which means the vehicle speed signal generated by the instrument cluster is adequate for the cruise control. Since I have verified continuity between the cruise control connector and the ECM connector it appears the problem is in the PCM.

[mdparrish]

I've been having the same trouble with the VSS signal. My vehicle is a '95 850 turbo. Seems the signal is getting to the instrument cluster, because the trip computer calculates average speed correctly. I also tested by resetting while driving at 40 mph and directly after the reset average speed matches the speedometer. I haven't figured out how to reliably test whether the signal is present at the TCM because everything I've been able to find online requires a breakout box for testing. Pins a1 and a2 are open where the TCM connects with ignition off, but without knowing whether or not there are relays at the instrument cluster, that tells me nothing. Looks like the only reliable way to test is through the breakout box and the TCM online and present in the circuit. Were you able to find any work-around?

[precopster]

I hope you realise that there are two speed sensors on the gearbox. One is at the rear and the other is closer to the PNP.