Location Of No. 1 Speed Sensor ? + Trac Problem

[tts451]

Hi everyone. This is my first post. I've learned much already by reading many of your existing problems and solutions. My 94 LS400 has three issues that I am dealing with. the TRAC light stays on , the check engine light is blinking code 41 (TPS) and my O/D light blinks code 42 ( No. 1 speed sensor signal malfunction ) I brought the car to my local Lexus dealer who first diagnosed the main ECU was the culprit. Unfortunately replacing it didn't work. They then suggested replacing the TRAC ECU, but could not say for sure that it would remedy the problem. Well long story short, they offered to put my old ECU back in the car and charge me a fair price for their labor. I'm going to replace the TPS and the No. 1 speed sensor but I'm not sure if that speed sensor is on the transmission? Also, can it be cleaned or only replaced? Any advice will be greatly appreciated. Sorry for such a long post....I owe you all a beer.

[ko90ls]

there are two speed sensors on the tranny. i know cuz i bought both of them to find i needed the speedometer sensor. my O/D light flashed just like yours but my speedometer didn't work either. sorry don't have trac so no info on that light. the speed-o sensor fixed both problems.

[tts451]

Do you know which speed sensor is No. 1 and which is No.2 ? Also , where is No. 1 located ?

Thanks again

[ko90ls]

It depends on which year you have... but the tranny should be the same in general save some minor changes from year to year? here is a schematic on the tranny and it shows the speedometer sensor and the speed sensors (yes these are different)

here's a pic of the speedosensor send from lexus-parts.com