4t45e skips 2nd.

[BlackJack]

I already PM'ed this to sharkey, but thought any of you might have some insight.....

Vehicle: 2003 Olds Alero, 3400 V6, 4t45e trans.

Problem: when selector is in D or 3, from a dead stop, it will not shift into 2nd. It will shift to 3rd when criteria is met (MPH). It does not slip, it just wont shift into second at all, because I see the PCM commanding 2nd (with PT scanner and "gear" guage running), but it keeps revving to redline in 1st though the scanner shows 2nd, until MPH for 3rd is hit and it skips right over into 3rd.

If I start with selector in 3, it will go through 1st, and I can manually select 2nd and it will go to 2nd, but then wont shift up to 3rd even if I select it.

I can then stop the car, place the selector in 3, and it does it all over again, goes through 1st and pegs redline (can tell by fuel cutout) then skips over to 3rd once I let off it again.

Already troubleshot: I disconnected the PCM connectors, pulled the tranny cannon plug, and ran an ohm-meter for continuity test. Number 4 pin (1-2 shift solenoid) was fine all the way to the tranny connector. Number 44 pin (2-3 shift solenoid wire) tested good also. So it isn't a wire problem with those two.

Any other ideas?

Oh yeah, there's an insane amount of heat near the selector/sensors on the top of the tranny where the linkage connects because of the turbo, could that also have an effect on things?

[gectek]

heat and trannys dont mix, but i would look at a diff scan tool, to see if the outputs and inputs are what is needed.

also again with the codes. usually something this bad would show a code if it is electrical, and possibly if it is mechanical it would show also, with the output shaft speed sensor and the logic on that circuit. but the code may not turn on the ses, but still be in the history. so i would go to a reputable shop and just have the codes read with a good scan tool.
here is an apply chart also, when the solenoids switch on

[BlackJack]

That chart is exactly what I was looking for...thanks.

Then what I'll try next is putting a tester in line on both circuits to see if both grounds are actually "off" when it's commanding 2nd. I think if there is a short somewhere in the line, the test may actually show continuity, but not distinguish if the wires are making contact elsewhere to ground out..... which though the PCM commands second, a ground is provided somewhere that isn't supposed to be, if 2nd is supposed to be "off/off".

[gectek]

well those solenoids are applied ground by the pcm...iirc, they have voltage al the time and are ground switched, if you need pin locations or anything else with the trans, let me know i have it all

[BlackJack]

actually, yes. I could use a diagram of the front tranny plug pins, and the connectors on the linkage sensors on the top rear of the tranny as well. I have the full PCM pinout diagram for my 2003 Olds Alero already. The harnesses for both look like they were heated pretty good.

[gectek]

ok here we go, first 2 pics are the harness side, last one is the trans side

if you need the electrical diagrams or resist values, i have those also

[gectek]

and here is the elec diagram for the pnp switch, and the pinouts
first one is the PNP harness, second is diagram and third is the trans range switch harness

[BlackJack]

ok, finally got around to printing those out, and they look really helpful, but the image sizes are too small for me to read the print. When I enlarge the image, it blurs the print and still can't read em. Any chance you can post larger images or at least link me to the originals online?

[gectek]

i can email em to ya