Transmission Shifting issue: need help please

[creeg]

Yep, that sounds like the problem Im having.
I was able to catch it in action- but its a very shaky video (sorry about that)
https://www.youtube.com/watch?v=LW_X...ature=youtu.be

It even trips the "check trans" light. You can see how it misses the shift at 27 mph, then revs up to trip the check trans. It usually doesnt go as far as tripping the check trans light, but you get the idea of what is going on.

If it was just a sporadic thing, I would not care as much. But it happens multiple times, EVERY time I drive my car. Its very frustrating, and Im worried Im causing damage to my transmission.

If anyone has any suggestions, Im open to ideas.

[Y33TREKker]

Does it make any difference if you change the current position of the Power Mode switch? (Didn't see it's indicator light on the dash so assuming you're running full time with it off?)

[evillecutter]

i believe this trans should never have been put in this vehicle - or any vehicle for that matter

[creeg]

Thanks Y33TREKker, I will turn on the power mode on the way home tonight, and see what happens.

More to come.

[creeg]

Still getting the missed shift in power mode.

[Y33TREKker]

Did your current mechanics have any other suggestions for where you might be able to go to get an actual diagnostic code for the "Check Trans" light you're getting when this happens?

I know you said they had a diagnostic hooked up while driving earlier in the thread, but it seems that actually having a specific code to work with would be the next best logical step to take as opposed to just starting to throw parts at the problem.

[creeg]

Thanks Y33TREKker-

I have had the codes checked out with 2 different code readers at 2 different shops. The first shop was unable to get a reading off it, so I took it to a different shop (at the recommendation of the first shop) and they were able to get a code, but it was a non-descript code (Im still looking to see if I have that code written down somewhere) that was not much help.

[creeg]

Ok, new development in the ongoing saga of my stupid transmission:

The other day, I started up my VX, and was shifting into drive. I went a little too far and accidentally put it into 3, realized what I did, and then shifted into D. The thing is, I had already started giving it gas as I was shifting, so I think it did something weird. I didnt notice anything strange, but when I looked at the instrument panel, the D light was not lit.

I drove it for a bit, then stopped and turned off the car. I restarted, shifted into all gears while stopped, and checked the dash lights. All shift lights come on when appropriate, except for D.
I have driven it a couple times since then, and the D light still will not come back on.

Does this give anyone any ideas as to what I need to have replaced next in my quest to fix this issue?

As a recap (to those that have not been following:

I have an intermittent missed shift at 27/28 MPH. It wont shift into the next highest gear somethings.
I have tried to get error codes, but it doesnt throw any.
I have replaced the Mode Selector Switch with a new one. That did not fix the problem.

[tom4bren]

shifting from 3 to D whilst moving shouldn't cause any damage. Tranny's are made to be able to do that.

[MSHardeman]

Maybe it's just a horrible coincidence and your Drive indicator bulb decided to burn out at just the right (wrong) time.

If you're driving it then it is obviously in gear. Have you gotten it up to highway speed to see if it drops into overdrive? Other than pulling the instrument cluster to see if the Drive bulb is burned out, I would think highway speed would be the only way to see if it is getting/can get out of third gear.

[Y33TREKker]

Under the drivers side of the dash to the left of where your brake pedal hinges there's a small cluster of what looks to be from three to five electrical connectors.

The very top connector on the left only has one wire in it.

The vertically-aligned rectangular-shaped connector to the right of the other connectors is for the Automatic Trans Shift Indicator Control Unit.

You might try unplugging that connector on the right and plugging it back in just to make sure it's seated properly. Given it's location, maybe it got hit by your foot at some point and something happened? And if you're going to check it out anyway, no harm in giving it a good once over just to make sure all the wires going into it are seated properly too.

Wouldn't be the first time an electrical gremlin issue has been solved on one of these VX's by just re-seating a connector anyway.

[creeg]

Thanks Y33TREKker-

I checked, and reseated that plug. No gremlins present, still have an unlit D light.

[creeg]

Are there any other cars that have this transmission? Its a GM tranny, wouldnt they put it in anything else?

[MSHardeman]

This is what the Wikipedia says:

http://en.wikipedia.org/wiki/GM_4L30-E_transmission

[bartmanS4]

That wiki is interesting. I didn't realize the Rodeos used the same trans. That mean there should be a lot more junk yard parts than I would have thought. Not that it matters for me. Hehe