I just purchased a 1992 LS400 with 98000 miles on it. Overall, I’m very
happy with the car. I’m slowly working out the few defects it has.
Using my GPS laptop, I’ve discovered the speedometer is off by 4 mph at
80 mph. That is, my speedometer reads 80 mph, but my actual speed is
84 mph. When the speedometer is 15 mph, the GPS reads 16 mph.
When the speedometer is 45 mph, the GPS reads 48 mph, and so on.
The problem is linear. The faster I go, the more it’s off.
The speedometer needle moves smoothly and all instrument cluster lights
work properly. I clocked between mile markers and the odometer is exact.
I put new Michelin MX4V+ 205/65R-15’s on, which are the correct size.
I have the same tires on my 90 LS400 (238,000 miles) and the speedometer
and my GPS are very close. The GPS clocks my actual speed as a hair slower
than the speedometer, which I can live with. At least it’s constant.
I have scoured Lexus board and cannot find this exact problem. If it were
the VSS, I would think there would be additional symptoms. I thought
maybe there was a speedometer gear at the end of the speedometer cable
that goes into the transmission, like (gulp) Fords, but I don’t know.
Is anyone familiar with this problem? Where is the VSS located exactly,
And what does it look like? Is there 1 speedometer gear somewhere?
I can use parts out of my 90 LS for troubleshooting, but don’t know where to
look!
Thank you all for your time. This is an awesome board. I’ve already
repaired my hood shocks the Mighty Max way, and more, thanks to this
Board. I still haven’t found an 8” 2 ohm subwoofer though, but that's for another thread.