My car just threw a P0500. Other symptoms are:
Given those symptoms I'm thinking it's some electrical problem in an area common to those two.

But while reading the various P0500 posts and also the diagnostics manual I find myself confused. All the P0500 posts discuss replacing the two transmission speed sensors. But aren't those two sensors covered by code P1725 and P1730?
The diag manual text for P0500 just refers to 'No. 1 vehicle speed sensor'. It could be the same as the 'counter gear sensor', if that is the transmission output speed. It's just not obvious to me.

Does anyone know for sure
(1) which sensor is the 'No. 1 vehicle speed sensor'?
(2) if lack of a P1725 or P1730 means the failure cause is not the sensor itself?

Thanks

 

OK, here's the scoop. BTW My car is a 1999 RX 300 AWD, and I have had the ABS light on for years.

It seems the P0500 'vehicle speed sensor' is being triggered by the ABS.
Steps I took:

• Cleared the DTC code. Started driving - code came back immediately
• Read the ABS codes: 31, 32, 33, 34. All four wheel sensors malfunction
• Cleared the ABS code. Cleared the DTC code.
• Started driving - speedometer worked again.
• ABS light came back. Read codes: 33, 34. Rear wheel sensors malfunction.
• Speedometer is still working

So I think there must be at least one working wheel speed sensor to provide the vehicle speed.
If this comes back I'll look for the easiest one to fix.

Also the tranny sensors don't seem to be a factor.