Fix for Broken Speed Sensor Wire?

[BentSpace]

My friend's speedometer stopped working on her 2009 Yaris. I went to investigate and found the black wire going into the speed sensor on top of the transmission was cut, probably by a mouse. Unfortunately it's cut right at the plug, so I can't really splice it back together. The dealer, of course wants to charge $1200 for a new wiring harness. I was wondering if there’s a way to open the plug and reintegrate the broken wire?

If not, my other idea was to find that plug in a salvage yard and cut it off with enough wire to splice it onto my friend's car. I wasn’t able to unplug her's, it’s kinda hard to reach from the top. It is a plug though, right or is it hardwired into the sensor?

If I splice in a new plug in, will that work or would the possible slight change in resistance screw it up?

Any other ideas for how to fix this thing without having to replace the whole wiring harness?