I get this code after driving in slow traffic. It seems to come on after maybe 15 1-2 shifts when going through slow moving traffic. This is the only time. If I wait until the traffic is gone and then go home the light won't come on, and it drives fine.

The tranny was rebuilt about 18 months and 18,000 miles ago. Where should I start, what should I check first?


thanks

 

You can try a fluid flush. If that doesn't work, the tranny will likely need to be opened.

Steve

 

What transmission is it? I suspect the 4R70W. They have updated 1-2 accumulator piston and springs. The parts are cheap and you can do it thru the pan with VB in place. I had a 1-2 shift code in mine and I did that first. Ended up being the S1&S2 solenoid pack. I would do the accumulator piston first.

 

You're right on the 4R70W. I had the tranny rebuilt about a year ago. They said they updated all the parts that had updates.

How involved is changing the accumulator piston and spring? I haven't ever done much tranny work, besides changing the fluid.


Where would be the best place to order the parts and the shift solenoids? If the solenoids aren't too pricey, I'll probably just change them out while I there.

 

The updated parts you can get from dealer. I want to say the piston and cap, and two springs were ~50 dollars. It is fairly easy if you are mechanically inclined, the Vb can stay in place for the 1-2. You need basic hand tools and large snap ring pliers. Most difficult part was compressing the cap to reinstall the snap ring. A great trick i figured out was a large "C" clamp to hold the cap down. The S1&S2 solenoid pack was also about 50 dollars at dealer. I would do both if it was me, I did them separately and of course the last one fixed it. I hate ATF baths enough I would do both at same time.

 

I called the dealer to ask about the parts and they told me all of the solenoids are separate. There isn't a solenoid pack. He said I would probably want the shift control solenoid. Does that sound right?

 

There are several solenoids in the transmission, there is TCC for torque converter lock up, EPC for pressure control, and the S1and S2 that control shift from 1-2 and 2-3 . The S1andS2 are the "pack" of two.