Najeeh

Hello,

I need a schematic of the internal circuit of the speedometer in 90-92 Celsior. The speedometer and odometer work at a very slow rate than the actual. If someone has a schematic, I would be able to check whether or not an IC has failed in it.

Thanks

Yamae

It's not available at all. Toyota and Denso never release it.
All you need is to analyse the board using your skill and make a schematic all by yourself. That's the way we should do. We even need to use an X-ray machine.

dicer

Ask Yamae, have you checked the speed sensor yet?
And that is a huge problem, with all the electronics on any older car, they should release that info. I know there are dedicated outfits that do specialized reverse engineering of things like ECU's for older cars, just so rebuilders can fix the things. I really don't get it why the old stuff is so secret? But then if everybody could keep fixing the old stuff they would never sell new stuff? I guess some people always have to have a new car though.

Contact Tanin auto electronics in Wisconsin and if they can help pm me the info too. It is way to costly to send it from Pakistan to there so make sure they know where you are.

Najeeh

Well that's a bugger. I'll try my best to make a schematic.

dicer

I would be interested in a copy if you do.