Twinklebee

Normally I'm pretty good at guessing what's wrong with a car... but that's before all the computer parts came into play.

I have an '08 xB with 128K miles, auto trans, remote start, no major mods and pretty much up to date on all the maintenance. I bought her in August of 2007 in Chicago, Illinois but I moved to Phoenix, Arizona in June of 2008.
About 15K miles ago, I would get an occasional slip from 1st into 2nd while driving. Not consistent, no codes would throw, no check engine light would come on. Every once in a great while, it would happen into Reverse and also 2nd to 3rd gear.

A month ago, I started the car with my remote start (as normal) when I walked out of the door at work and the ECU had crapped out. I had her towed to my mechanic, had the ECU replaced and after two days, took her home. On the drive home, I stopped at a red light and the rpms dipped to below 500 and the car felt like she was going to sputter and jump forward - like an old beater dying it's last death. It happened at every red light and I called my mechanic immediately. Took her back and the mechanic reset the ECU. Took the car home again and now I'm having problems with slippage from 2nd to 3rd gear. The sputter of the low rpms doesn't happen anymore, though. I took the car to my mechanic yesterday and the fluid is the right color, consistency and not burnt and there's no reason why it should be doing this.

The problem is specifically this - After driving the car for at least 45 minutes in the HOT weather in Phoenix, if I accelerate from a stop, the shift from 1st to 2nd is good. The shift from 2nd is a high rpm followed by what feels like a slip from trying to catch the 3rd gear and jump forward in the drive of the car. Normally the second or third jump, it feels like the transmission catches and away we go into 3rd. It doesn't always happen but it does most of the time. The same problem happens into Reverse from a stop - put the car into Reverse and the car feels like it jumps and the gear doesn't catch. Once it catches, it stops.

Any ideas as to what I'm dealing with?

r2d2michael

Normally the ECU tells the tranny what to shift into and it has been a known problem on older Toyotas where the ECU starts to fail and tells the tranny to shift all over the place. (2001 RAV4's)
So not only do burn out the ECU but your tranny also. If it is still doing it with the new ECU it could just be a bad tranny. You can find used one for less than 1000 and 20-60k on them on eBay.

Or maybe a bad connection from the shift solenoids

Twinklebee

I talked to my mechanic and he's going to look at the solenoids and connections. Thank you so much for the reply.

99_xc600

Sounds like the valve body within the transmission

jtmaldonado06