We've owned a 1996 Pontiac Sunfire for the last 6 six years and I now use it as a work car for my daily 80 mile commute. It has the 2.4 DOHC engine, 4 speed automatic transmission, and 115,000 miles on it. Yesterday the transmission began acting up. It would shift hard from first to second gears, and not shift into third at all until about 40-45mph and then it would violently bang into and out of that gear. The "CHECK ENGINE" and "ETS OFF" lights also came on. I nursed it home at low speeds so it would not shift out of second gear. When I put my scan tool on it, trouble code P 758 was stored in the ECM. It says this is a shift solenoid.

So, is my tranny fried? Time for a rebuild or can this solenoid be easily accessed and replaced? Where is it even at? Any thoughts or ideas would be appreciated. I've already located a used transmission with 66,000 miles for $400, but I'd rather not go through the hassle of swapping in a used or rebuilt transmission if I don't need to.

Thanks.

The GM 4T60E (4 speed automatic) has an "A" and "B" shift solenoid. They are located on the valve body behind the side cover and sit across from each other on the bottom if I remember correctly. If you are getting a check engine light with a code for a shift solenoid it is most likely an open or shorted circut. The wiring that goes from the front of the case (on the inside) to all the solenoids often gets worn through by rubbing on the inside.

First buy only GM replacement parts. Get an "A" and "B" solenoid and an internal wiring harness. Also get a side cover gasket (two pieces) and an axel seal. You might as well do a trans service while you are at it. You only need a filter as the bottom pan gasket is reusable unless damaged. Do this first as it will drain the fluid from the side cover (less mess).

Support the vehicle by the unibody frame just behind the front subframe. Remove the left power steering rack bolt, and the left motor mount bolts. Remove the left tire, any covers on the left wheel house and the bolt for the left ball joint. After you pry down on the lower control arm you can pull the axel out of the trans without removing the axel from the wheele hub. Place a jack under the subframe on the left and remove only the two frame bolts on the left, lower the frame. Now you can remove the cover. The solenoids are removed by removing the clip that is accessable just in front of the solenoid in the valve body. Make sure to route the new harness through the little hold downs and away from moving parts.

The one bad thing is (and generally doesnt set a code) that each solenoid has a little screen that keeps derbis out of the solenoid. They are located between the valve body and the plate that is bolted to the trans housing. They often break and cause similar situiations. But since you are getting a code, Im sure its electrical.

If you need any tips while you are doing this, feel free to call me at 407-957-3617. Im here everyday until about 9pm

Good luck,
Team Ferret

Damn! TeamFerret beat me to it!.




Not really. I don't know jack about transmissions but he sure seems to. Aint it great to have such a diverse crowd to glean information from? If you can't find the answer to your question here then you don't need to know!

TeamFerret, thank you very for much for your informative reply. That's almost exactly what I wanted to hear, that I should just be able to replace the solenoids and have the transmissions back in good running order.

My scan tool did say that the B solenoid was the malfunctioning part, but I'll go ahead and replace the components you suggested to as well as change the fluid and filter while I have everything apart.

Sounds like it a bit of a chore getting to the solenoids, but nothing I can't handle with a bit of time.

I'll be sure to give you a call if I need any further assistance. Thanks again.



Ain't that the truth. It's amazing what a broad spectrum of knowledge is available here.