The front and rear sensors are both the same in this car (1998). The only difference is the length of the cable.
The two white wires are the power for the sensor heater circuit and I don't /think/ it matters which order they are connected, but I always try to keep them straight just in case.
The black and grey wires are the signal wires. I don't actually know why it needs two signal wires and not just one like the older 7xx sensors.... can anyone help with this?
I believe this is the same for all 850s.
probably also the same for 1999 and 2000.
I have no information about other years.
The bosch universal sensor is the exact same 'sensor' as the exact-fit sensor, it just doesn't have a connector on the end of the cable, so you have to splice it on to your old connector. This is not a problem if you can solder.
I am currently using a 'front' sensor that was spliced on to the longer rear cable as my rear sensor and it's working great. Actually I discovered the previously installed sensor was going south and making this switch fixed a persistent MIL for me.
--
1998 V70 AWD->FWD->AWD Turbo 215k+
|