Speedometer signal goes through abs/tracs module. You have a bad abs sensor(s),their wiring or bad abs/tracs module...VOL-FCR or dealership is needed to read the codes. TRACS is always ON by default. You can turn it off by pressing the switch and TRACS OFF will illuminate on the cluster. Usually...w...

850 OBDII app will work but with specific obdII adapter. I never used it but here on MVS are plenty members that knows how to use it. I'm affraid that your abs module might be replaced somewhere in the past since it always turn on both abs & tracs light. As far as i understand...you have just Ab...

On my 2000 V70 the signal for speed is taken from the LHF wheel sensor.

Misha, great info as always!

Neil.

Yes.

Neil.

Check the wiring harness in the trunk where it comes out from the side panel and connects to the LH trunk hinge. These wires often break with age there.

Neil.

If you have had coolant leaked into the carpet it is hard to remove it and get it dried out. Even removing the carpet completely if I recall is not easy as the carpet is joined un under the dashboard. You could cut it and remove it completely which would allow you to carefully pressure wash the foam...