09 2.4 Auto Downshift Clunk at Stop

[marq]

This was something that happend about 5 times yesterday, as I come to a stop there is a noticable shudder just before the car fully stops, feels like the trans is having difficulty downshifting.

09MY, 43K miles,will be stopping by dealership after work but I've searched and didnt see any other posts.

Anybody hear anything related?

[Houston]

What you describe is exactly what my 2009 2.4 automatic has done all along. If memory serves me correctly, there was a TSB or whatever it's called that was supposed to correct this problem. I had it (maybe there were two of those TSBs) taken care of by the dealer. Although it (or they) changed the feel a bit, the problem still exists. According to the dealer this problem won't hurt anything. Time will tell. I totally agree with your concern.

Although you haven't found it - and I haven't looked - there used to be a long thread on this board about this problem.

[Jamesp]

My 2.9 09 was doing the same thing when I came to a stop and the dealer reprogrammed the transmission during the gas pedal recall.
My Vibe drives like a different car now with no hard down shifts when coming to a stop. They told me it would take the transmission about to weeks to relearn the way I drive.
I'm very happy with the outcome of the reprogram.

[vibenvy]

Yes, there was a TSB (Technical Service Bulletin) issued for this problem. I had it done once and it didn't really seem to do anything, then I had it done a second time when GM issued a revised TSB. The second time made a huge difference. Mine will still do this every once in a great while, but it is much better then it used to be. The TSB is pretty simple and only requires the dealer to re-flash the PCM. It shouldn't take them long to complete and since it's a TSB, it's free.

Here's a thread about it.

Here's another thread about it.

[ParknVibe]

Yes, there was a TSB (Technical Service Bulletin) issued for this problem. I had it done once and it didn't really seem to do anything, then I had it done a second time when GM issued a revised TSB. The second time made a huge difference. Mine will still do this every once in a great while, but it is much better then it used to be. The TSB is pretty simple and only requires the dealer to re-flash the PCM. It shouldn't take them long to complete and since it's a TSB, it's free.

Here's a thread about it.

Here's another thread about it.

Has this TSB re-flash improve the MPG of the 2.4L Vibe?

[vibenvy]

Has this TSB re-flash improve the MPG of the 2.4L Vibe?

No. I don't see how it would.

[ParknVibe]

Has this TSB re-flash improve the MPG of the 2.4L Vibe?

No. I don't see how it would.

by making shifting more accurate....

[vibenvy]

by making shifting more accurate....

I honestly haven't paid attention.