chizz95

Obd1 sc300 na-t about 300rwhp 10psi right now.

I was driving the other night normal on the highway crusing about 75mph in overdrive prob 3000 rpms and all of a sudden jumps up to around 4500rpms ...

Overdrive isn't working can't find a fuse for it..
Some people are saying try a new ecu? No CEL ,some people say a solenoid in trans?

If anyone has had similar experience help a brother out,thanks-chad

nlc

Id like to hear the solution to this problem also..

chizz95

Bump anyone...?? Think its time to throw in the jdm tt auto trans
(valve body swap)

Cleet

iTrader: (5)

Ecu fixed my 92 with the same problem. Ecu's can be found for under $100 shipped too. Pretty common so I would give it a try.

chizz95

If anyone loses there overdrive, try a new ecu first.

Bought a Eco off eBay for $85 shipped installed it and I now have overdrive again.

Thanks CL for the help..!!

mikeboost4

I am having the same issue I don't have O/D

My Lexus is a 1993 sc300 and I removed the ECU and found it had already been rebuilt prior previous owner. I took the car to buddy shop because he has a lexus sc300 1992 and swapped computers and car would not start with his computer. I will test the speed sensor and see if that could be causing the problem, but I will get to the bottom of this issue.