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2007 STS-V Wont Downshift Manually

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Old Apr 11, 2011 | 11:53 PM
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Default 2007 STS-V Wont Downshift Manually

With the stock tune, she downshifted practically whenever you commanded manually. After some adjustments with the help of some of our fellow members here also no problems. She will downshift automatically as commanded as well as manually. Car has had the trans tune for over a week now and no problems what so ever.... just smiles!

On saturday the car was on the dyno for about two hours and on the dyno she started to no want to downshift.

I think this is KEY. Also, strangely when selecting 1st on the dyno and accelerating to start the run, she wouldn't accelerate pass 1500rpms even if I put my foot through the floor. (I didn't) Eventually, she would suddenly surge and be "ok".

After the dyno, he complained that she didn't want to downshift manually. I thought, since these trans have a decent adaptive "learn" function, it learned some bad habits and should go away.

So, fast forward today. The owner of the car called me and told me that she still didn't want to downshift manually and that she had a surge/flair shift between the 2-3 and the 3-4.. but the 2-3 was more noticeable.

So, i drove the car and the 2-3 surge/flair was definitely there. Also, the trans wouldn't downshift manually. Again, It didn't do it before with the same tune so after doing a few tests and adjustments and after talking to PGA, I did a complete write and reset the fuel trims.

That cleared up the 2-3 surge/flair but the trans still didn't want to downshift manually.

I, again went through all the tables that could affect this (to the best of my knowledge) and I couldn't find anything that could fix the problem.

It seems that it not wanted to shift has nothing to do with the calibration. Something must of happened while on the dyno that has the trans acting weird. She shifts perfectly fine during every other mod, upshifts and downshifts, but manual downshifts are just not working... the gear number will just blink a few times when trying to down shift (i.e. "M5" 5-4 downshift, the "5" will blink) and stay in the same gear.

At one point she didn't want to shift out of 3rd, up or down but that only happened once. If you let the mph drops the trans will automatically downshift while in TUTD mode according to the TUTD partial throttle downshift tables. (Mph confirmed and working properly)

So, anyone know what might of happened? I'm thinking that it might be something as simple as pulling a fuse and we're good to go.

Oh, we pulled the negative for about 10 minutes and that didn't fix it.

Appreciate the help guys/gals!.

Oh, here is the cal.

http://www.hptuners.com/forum/attach...8&d=1302587084
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Old Apr 12, 2011 | 09:42 AM
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