Hello everyone! I seem to be having trouble with my Lexus automatic transmission. First off there are no cel's or anything unusual lighting up in the dash. When i get up to about 50-60 mph my car will not shift into overdrive properly. It will high rev doing 60 for about 10-15 seconds and the shift into overdrive. Then about 10 seconds later it shift back up into 3rd gear. It keeps doing this cycle for about a minute and then stops when its in 3rd gear and then about 5 minutes later do the same thing all over again. The car did have to much transmission fluid in it so i drained some and put a quart back in it to get it to the proper level. The transmission fluid that came out did look a little on the dark side but didn't smell burnt it smelt normal. Idk when the last time they changed the fluid or filter for the transmission either. I also had the ecu taken out and sent of to tanin electronics to put new capacitors in it a while back. My question is has anybody else had this problem and maybe a solution? Could bad tranny fluid cause this? Also my O/D light is not blinking on and off. Thanks in advance!

Forgot to mention the car only has 127k on it.

 

ReCap:

I did a transmission drain and changed the filter also. I inspected the magnets and i didnt see any metal shavings on them. The fluid was a darker red color but did not smell burnt. I went ahead and did a ohm reading on the 3 solenoid's that were there. 2 of them read 12.5 Ohms and the third read 13 ohms. I think these are good solenoid's. I drove the car but it did not fix the problem yet.

 

I have another Recap:
While driving at around 60 mph when the transmission is hot i can tap on the brakes and the car will shift into overdrive for about 5 seconds and shift back into 3rd gear. It doesn't matter if the car is in cruise control or not. If i repeat this process and after tapping on the brakes and the car shifts into overdrive and if i maintain the current speed without pushing in the gas pedal to hard it will stay into overdrive but if i accelerate to much it will kick out of overdrive. Anbody got any suggestions?

 

An update on the situation. I changed the Speed Sensor 2 wire and there was still no change

 

I had the same issue. Trans would shift into and out of overdrive. It would only do it during the summertime when its hot outside. I sent my ECU off to have it repaired and that didn't work. I purchased a Lexus remanufactured one off ebay and have not had a single problem.

Hope this helps.

1993 Lexus SC300 with 260,000 miles.

Thanks
Ryan

 

More question than any bit of help. I was driving down the interstate at about 75. When it felt like if somebody pressed the overdrive off button. Now if I hit the button it doesn't seem like anything happens. Would this possibly be an ECU issue also