speedometer stopped working with cruise control and o/d light is blinking on and

[13brett]

I have a 92 lexus sc400 and my speedometer stopped working a couple of days ago along with the cruise control, and the O/D light is blinking on and off. I know there is a seperate ECU for the tranny, could it be a fuse or something?

 

[Lextreme II]

Never hurt to check the fuse first. I think the US Version SC400 has an intergrated tranny control from the main ECU.

 

[13brett]

Do you know where the tranny ECU is? Or the fuse for it is?

 

[Zuffen]

You'll find the fuse in the fuse panel on top of the inner wheel arch under the bonnet.

The trans and engine ECU are a combined unit and it's below the clove box. Silver box around 6" x 5" x 1.5" with ECU written on it. There are a few boxes under there but none are owner servicable.

 

[Damien]

Could it be a problem with one of the speed sensors?

 

[13brett]

I have TEIN coilovers on it and the tires that were on it made the car lower, they were 215/35/18s and I was scraping on everything maybe it knocked something loose or messed up some sensor or something but I switched to 225/40/18s.Is the speed sensor in the tranny? I couldnt find any fuses that said anything about the tranny.

 

[Lextek]

Check the speed sensor located on the transmission tail shaft housing. The sensor may have failed or the nylon gear may have sheared. If the gear is damaged,check to see if the sensor spins freely. If the sensor spins ok, replace the metal gear on the output shaft of the transmission also. Moisture may have caused the metal gear to rust. This in turn creates a rough surface for the nylon gear to ride on, causing the gear to wear down and fail. After the repair, pull the EFI fuse under the hood for about 20 seconds. This will clear the codes stored in the ECU.