I'm rebuilding a salvage 2013 Transit Connect with automatic transmission and gas engine (US model), and everything was going great until I was finally able to drive it off the trailer. It reversed off the trailer just fine ... and then I found out that none of the forward gears are working, only reverse & park. In forward gears, it acts like it's in neutral -- engine revs freely, and the van doesn't move whatsoever.
I've read that this may be caused by a faulty vehicle speed sensor (VSS), because the transmission may refuse to shift between forward gears if it doesn't know how fast the van is moving. I think I've located the sensor (on the back of the transmission just above the axle). It's still plugged in, and there's no external signs of damage (though it has a bit of extra heat insulation around it along with a ziptie -- is that factory, or does it mean someone has screwed around with it before?)
So I'm fairly sure that either:
A) I have a bad speed sensor, or
B) My transmission is super- f***
Obviously, I'm hoping for (A), but I'd really like to be able to test it before ordering any parts that may end up not fixing the problem ... so is there any way I can test the speed sensor, given that I'm not able to drive in a forwards direction?
One idea is to pull it with another car down the road for a short distance with the ignition on and in neutral, then see if the speedometer registers anything.
Another idea is to put it nice and high on jack stands, so both front wheels are well off the ground, pull the parking brake (and maybe even chock the rear wheels) and then put it in reverse, which does work, hit the gas and again see if the speedometer registers anything. (Is the speedometer supposed to work in reverse, though? It should, right?)
But are there any better/safer ways to test the speed sensor?
(And while we're at it, are there any other things I should check that could cause the transmission to not work in any forward gears? Anything else I can fix short of 'replace the whole transmission' would be great! It was previously involved in a front-end wreck ... is there perhaps some safety interlock switch that prevents the transmission from going into forward gears in the event of an accident? I've heard of switches that will shut the engine off if there's an accident, so maybe that's possible? If there was such a thing, where might it be located, and how would I reset it?)