New truck, New problems. Need help with 1-2 shift bump issue...

[IgotQuestions]

2003 Silverado 1500 Ext. Z71 4x4. Automatic. It has that little slip/slide followed by an annoying bump/jerk when it shifts at low speeds from 1st to 2nd gear. I've read just about every thread I can find on the issue and I just seem to find more possibilities. 1-2 accumulator, 1-2 accumulator valve, solenoid, alternator sense wire. Can anyone help narrow this down??? I do all my own mechanic work...but not transmissions. I'm probably going to have to pay someone to fix this, but it would be nice to have a better idea of what the actual fault is here.

[C3pilot]

Clean your MAF sensor. I just did mine and I can't believe how much smoother it shifts. I didn't clean it because of shifting problems but found out afterwards that it can improve shifting. Something to do with how much line pressure is in the transmission??? Sorry I don't have a link to a how to but it's been pretty well covered. Make sure you use the correct cleaner! Let us know if it helps.

[IgotQuestions]

Clean your MAF sensor. I just did mine and I can't believe how much smoother it shifts. I didn't clean it because of shifting problems but found out afterwards that it can improve shifting. Something to do with how much line pressure is in the transmission??? Sorry I don't have a link to a how to but it's been pretty well covered. Make sure you use the correct cleaner! Let us know if it helps.

 

I got the can of MAF cleaner and cleaned it. Probably runs a little smoother...but the 1-2 shift bump/jerk is still there. My research seems to point to the 1-2 Accumulator Assembly, particularly the plastic piston or o-ring being cracked or worn. Has any fixed this issue here? Can anyone confirm this??

[Brianibew]

I had an 2003 1500 for 10 years and always had the annoying 1-2 shift. Never got better or worse. 100k miles later, it was still the same. If you can live with it, don't worry about it.

[IgotQuestions]

It's to annoying. Gota fix it. Someone here must know something?

[efritz]

Ok, so with this issue, the most common external issue is the TPS, however, since you have an 03 you most likely have drive by wire (switchover year). If you have DBW, the most common issue is either a 1-2 accumulator cracked, or more likely, a worn/burnt 2-4 band.... The latter requiring a rebuild. You never said how many miles.

[IgotQuestions]

It has the electronic throttle body with the actuator/tps on the side there. But I have no check engine light...Can it still be bad with no check engine light though?