Need to find vss wire

[mattk50]

I just installed a Sony xnv-660bt

nav sustem and for the life of me I can't find the VSS wire to tap into. Is this even needed?I've heard that its not needed on some systems.

 

[n7gxz]

Normally that is only need for deadreconing (e. g. guesstimating when the sats are not in view).



Kevin

 

[rbattelle]

There is no VSS wire, per se. The system measures wheel speed based on inputs from the ABS wheel sensors (one in each front hub and one on the rear differential).

The cable to the instrument cluster is a PCI bus.

-Ryan

 

[n7gxz]

Actually there is a VSS wire, it comes off of the anti-lock brake unit and goes to the ECM and then eventually to the dash. The wire off of the anti-lock brake unit is pin 12 (dark green with yellow tracer). The signal maybe too high of a pulse rate for your GPS unit but you can try if you want.



Kevin

 

[mattk50]

Thanks guys--- after fooling with it it seems to work fine without it being hooked up.

 

[rbattelle]

Actually there is a VSS wire, it comes off of the anti-lock brake unit and goes to the ECM and then eventually to the dash. The wire off of the anti-lock brake unit is pin 12 (dark green with yellow tracer). The signal maybe too high of a pulse rate for your GPS unit but you can try if you want.

You're right. Except I think your color is wrong. It's cavity 12 at the brake controller, which was white with an orange stripe at least until 2004.



It connects to the ECM at connector C1, cavity 22 as a white wire with a tan stripe. This ambiguity regarding the wire color may be a mistake in my service manual, I'm not sure (there's no reason for the wire to have changed color between the ABS controller and the ECM, according to my manual).



I can't find a VSS signal line apart from the PCI bus cable. I'm not saying you're wrong, I'm just saying I don't see it in my diagrams.



-Ryan