Toyota Sienna Transmission - Error code PO770

I have a 1999 Toyota Sienna XLE. The transmission failed at 57,000 miles and was replaced under warranty. Now at 126,000 miles the check engine light has come on. The dealer says this is a PO770 error code and I need to replace the transmission for $3600. I am not having any problems at all with the transmission but I understand that the vehicle will not pass inspection as long as the check engine light remains on. Do I have to spend $3600 to replace a part that is working fine or is there some way to fix the problem at least until the transmission actually fails mechanically?

I am not an expert on this, but Googling shows P0770 as Shift Solenoid E Malfunction. And, one page says it is the solenoid which locks up the torque converter.

My 2002 Sienna has nearly 165,000 miles on it, and if it fails, I expect to take it to a good transmission place for rebuilding. It should be much cheaper than buying a rebuilt from Toyota. (I am assuming that is a rebuilt, since with labor a new one would probably be a lot more, but you did not say – and I am not an expert as I said.)

Scout the Mechanics Files somewhere on this URL for a good transmission rebuilder near you, and ask them what it costs to fix this problem.

A lot of people believe it is much cheaper to go to an independent mechanic, if you can find a good one. I go to the dealer only because in my community the really good independents are so swamped they want to keep your car for several days and that is not practical with only one car.

The $3600 is for a rebuilt. My local mechanic says he can do it for $3000. Since the car seems to be running perfectly well except for the check engine light I plan to keep driving until the transmission fails or it comes up for inspection in October 2010 whichever comes first. I hope this is a sensible approach. Many thanks for your advice.

You really need a second opinion.

The dealer probably has no idea why the code is being thrown - could be as simple as a little gunk in the solenoid or a little problem with the connection.

They’re looking at an 11yr old vehicle with 126K on it. From their chair, the most straightforward route to making money while putting you back on the road is to just replace the whole thing. For them mucking around with your old high mileage transmission will not be worth the trouble.

You need to ask around and find a locally owned, independent shop that specializes in transmissions. Have them look it over. You might get the same story from them but you should have a second opinion.

How often has this transmission been serviced? If it is truly behaving normally except for the code having a transmission service (drop pan/replace filter) couldn’t hurt. Talk to the local trans shop about that.

Sounds somewhat like my problem. I have a 2000 Toyota Sienna, it currently has about 195,000 miles on it. At 98,000 miles I had the transmission replaced for free under warranty. Does anyone know if Toyota has a warranty on their REPLACEMENT transmissions? It’s fairly well known that Toyota extended their warranties from 70k miles to 100k miles on the transmissions. But does that mean a new transmission installed at 98,000 should last till 198,000, and if it doesn’t, is it also covered under warranty?

Hey, Rock Auto has the 2000 Sienna transmission for $1.750 after a core charge of $415.

Thanks for all suggestions. I will follow up. I have serviced regularly with dealer so expect that regular transmission service was done. Will have to check back on records. The replacement trans was installed under warranty at 57,000 miles but I believe the replacement carried and inferior warranty. I think one year. But certainly worth a check. If it has 70k warranty then 57+70 =127k just over the 126.5k mileage currently showing. As a last resort Auto Rock may be the way to go. Thanks

my daughter’s’99 sienna w/150k lost 1st and 2nd. autozone employee gave the computer a dope-slap and it regained 1st and 2nd. dealership says trans needs to be rebuilt. i’m wondering if it’s just a computer glitch. any references or directions i might look?