Car shifting itself in Manual mode?

[Ifixtheinternet]

Hi all,

 

Just became a proud owner of a 13' 3.6R with 30K miles, and loving it so far.

One issue, as stated, is the car is shifting on it's own sometimes from 2nd to 3rd when in manual mode using the paddle shifters.

 

1st to second is always as expected, it will let me shift at redline.

But about half the time, it will shift from 2nd to third far before I would hit the paddle, like around 3500-4000 RPM. To my understanding, manual mode should only downshift automatically, not upshift.

 

Do I not understand something about how this system works, or should I take it in?

 

Thanks.

[FLlegacy]

The ecm will shift itself up to save the engine from possible over-revving try easing up the rev range and see if it holds the gear that way. It may just be preemptively shifting up. You may need to have the dealer reflash the tcm/ecm.

[Ifixtheinternet]

Thanks for the help!

 

Just to clarify, are you saying shifting earlier from 1st to 2nd might eliminate the auto shifting from 2nd to third? I try to shift between 5500-6000 normally when in manual mode.

 

I don't think shifting at 3500 RPM is saving the car from anything, but please correct me if I'm wrong. If this was a safety feature, I would expect the self-shift to happen closer to redline.

 

Only scenario I could think of, is if this was tranny fluid temperature based, and because the previous redline shift pushed up the temperuture, the car then auto shifts the next gear?

 

The manual does not say anything about this feature that I have found yet.

 

I spoke to the dealer and they basically said it's normal "when the car wants to shift", but they couldn't elaborate on why it would want to shift, (temperature, load, speed?)

 

If a TCM flash couldn't hurt, I'd do that for sure.

 

Thanks again, will play around more with it on the way to work.

[FLlegacy]

There is a good possibility that your pushing the paddle shifter is causing the early upshift. Try just running it without using the paddle shifters. If you hit redline or close the trans may be shifting and then you push the paddle shift up and it shifts again. In manual the trans will upshift on its own at redline.

 

Sent from my SAMSUNG-SGH-I337 using Tapatalk

[Ifixtheinternet]

That makes perfect sense and probably exactly what is going on.

I will confirm on the way to work.

 

Now this begs the question:

Is there a difference between auto mode and manual mode (letting the car shift) at maximum throttle? Or is that not a safe way to operate the car?

 

Thanks.

[FLlegacy]

The car will not hurt itself, so in that sense no. Will it increase wear on the bearing, pistons, rings, clutches, torque converter...yes safe to say it will. I generally use sport mode when I want better shifting but out Tribeca has no paddle shifters and the 3.0 likes to rev.

[gimpydingo]

I've posted this as well a while back, with no one else experiencing this.

 

This happens on my 07 LGT, but not my 13 3.6R. I can leave my 3.6 in manual mode and it will go to redline in every gear (shifting when it hits redline). My LGT likes to jump from 3rd to 4th under heavy acceleration at around 4000 - 5000 RPM's. If I shift in 2nd I usually end up hitting 4th gear since the car shifted the same time I did.

 

It seems a bit intermittent, but easier acceleration (does this car even do that?) seems to mitigate the issue. Or just S# automatic mode getting on the freeway.

[FLlegacy]

I believe the 07 5eat was different in some slight ways from the new models and probably has different programming. Have you tried having a tuner look into why the tcm is calling for a shift so soon?

[gimpydingo]

I had talked to Dave (Cryo) when he tuned me years ago. Was unsure why. The dealer had flashed the TCM as well, but they stated it was so the tranny didn't get damaged. As soon as I get my a/f issues resolved, I'll be getting a DP and a new tune. I'll be asking again at that time.

[Timothy.B]

I have this happen sometimes as well. At stock, the transmission shifts kind of slow so I'm guessing what is happening is the computer is just over compensating the shifting delay. West_minist could help you with a TCM reflash. I haven't done my exhaust yet so I haven't bothered with it.

[Ifixtheinternet]

There is a good possibility that your pushing the paddle shifter is causing the early upshift. Try just running it without using the paddle shifters. If you hit redline or close the trans may be shifting and then you push the paddle shift up and it shifts again.

 

This.

 

I made 6 passes in manual mode:

 

2 allowing the tranny to shift on it's own:

Every shift was at redline.

 

2 w/ paddles at 5500 RPM

Every shift as expected, 5500-6000 RPM

 

2 w/ paddles at 6000 RPM

1st to 2nd at redline, then drops to around 4800 and shifts at 5000 to 3rd.

This happened both times.

 

So basically you cannot pull the paddle too close to redline or it counts toward the next shift, and it shifts as soon as it is a viable option.

 

This is still very annoying, as it should ignore your shift if it is too close to redline, not count toward the next one. i can't imagine a scenario where that is useful.

Do you guys think a TCM flash would do something for this?

 

Thought the paddles would b kinda fun, but if they make the car slower, then not really.

[FLlegacy]

It's not for speed more for control, again I think what's happening is the tcu is already sending the shift signal and then you are sending one, so the trans shifts on command from tcu then again on your command. The 5eat is a bit slow to react to manual shift requests so that doesn't help. I don't know that shift timing can be changed through tuning.

 

Sent from my SAMSUNG-SGH-I337 using Tapatalk

[Ifixtheinternet]

It's not for speed more for control, again I think what's happening is the tcu is already sending the shift signal and then you are sending one, so the trans shifts on command from tcu then again on your command.[/quote

 

Perhaps you missed your quote in my previous post, but I am in complete agreement with you on this, and proved it through testing.

 

 

I'm enjoying letting it shift in manual mode, it's a pretty quick car compared to what I've had in the past.

 

 

I agree the paddles are pretty slow, and the delay doesn't always seem to be the same between gears, so you can't always anticipate properly either.

Sometimes it takes over a full second, which I think is ridiculous.

 

 

So I suppose these are better for engine braking downhill or eliminating the gear hunt uphill I've read about?

[dgoodhue]

Have you tried turning off traction control to see if that affects the shifts? I used to travel regularly for work and rented a lot of different cars. Some cars react differently with traction control off (sometimes good and sometimes worse).

[Ifixtheinternet]

Have you tried turning off traction control to see if that affects the shifts? I used to travel regularly for work and rented a lot of different cars. Some cars react differently with traction control off (sometimes good and sometimes worse).

 

No I haven't, but I'm gonna go out on a limb and say that if shifting sooner eliminates the problem, it likely won't be affected by tracs. Even if that fixed the problem, I'm not sure I'd want to try racing the vehicle without traction control.

[Ifixtheinternet]

I have this happen sometimes as well. At stock, the transmission shifts kind of slow so I'm guessing what is happening is the computer is just over compensating the shifting delay. West_minist could help you with a TCM reflash. I haven't done my exhaust yet so I haven't bothered with it.

 

I'm new to mods of any kind and Subaru, so forgive the dumb questions.

 

Do you think "ignoring" driver shift input around red line can be accomplished with a tcm flash?

 

Have you not done it yet because changing the exhaust will make it different, or because it's not worth it without any mods?

 

Is a TCM flash going to void the warranty? I have 70k miles left on the b2b so not about to give that up.

 

Thanks.

[Timothy.B]

I haven't had anything done yet because he does both TCM and ECM. I wanna change out the stock axle back exhaust before I bother to have it done. That way I can just do the ECM and TCM at the same time.

 

Here's a thread about it:

http://www.xtremeracingtuning.com/forum/viewtopic.php?f=6&t=509

 

I should note that some of those are people with the 3.0 H6

 

I don't know about the warranty. He told me you can switch back to stock when you take your car in, just to be safe.

 

I know you can also have your redline bumped up a little higher too. To 6750 I believe.