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H6 3.0 ECU and Tranny upgrades?

6237 Views 8 Replies 6 Participants Last post by  Seabass
Love my 2006 outback - except for one thing. I cant stand the way this auto tranny shifts. Its sluggish when I give it the gas, I cant get it to down shift or up shift when I want by modulating the gas pedal, and going up a hill (even not that steep of a grade) its constantly hunting for gears unless I have it floored

Are there any ECU mods out there that can fix this? I looked at the cobb controller, but that seems to only be the for 2.5 and 2.5 turbo engines.....

help!
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Miles on vehicle?
Has the ATF even been changed? If so, with what fluid?
60,000

Fluid was changed a week ago - shifting was improved but still sluggish and it did not affect the hill issue - I'm not sure what fluid was used, I took it to a subaru independent
You might call and ask.

For vehicles that came with the Subaru ATF HP fluid, mixing in the older style Dex III fluid can cause some shifting issues.

But the 4EAT and 5EAT both seem to be gear hunters.
Take it to a dealership, And ask them to do an air bleed and relearn on the tranny, and have them check for " Logic updates "

Should only be an hour's worth of labor... and make DARN sure the shop used Subaru's HP fluid. failure to do so can cause serious torque converter lock up shudder and poor shift quality..

What gas are you running ? The 3.0R 's have a fairly advance timing map Vs. shifting..
If the knock sensor is pulling out to much timing, the transmission isn't going to act the way it should, The car will go into a fail safe type mode, and pull out quite a bit of power.
What gas are you running ? The 3.0R 's have a fairly advance timing map Vs. shifting..
If the knock sensor is pulling out to much timing, the transmission isn't going to act the way it should, The car will go into a fail safe type mode, and pull out quite a bit of power.
Can you elaborate on that?

(start hijack) Mine has been run on reg fuel since new and has similar issues on hills.(end hijack)

Are you saying that when torque is needed at low rpm and the wrong gas is in use the electronics prevents spark knock; reducing power and the trans downshifts raising rpm? That creates the hunting.... Interesting!

I just thought the H-6's just didn't have low rpm power... Learning new stuff everyday!

If this is a fuel/adv timing issue I wonder if there is a different shift module for high altitude (less power) that would off-set this?


kawasakiguy37, Where are you located and what fuel do you use?

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The owner's manual states that the H6 is designed for optimum performance on premium fuel, although it can compensate for lower octane. You might try a few tanks of premium and see if it adjusts.

Unlike the H4 which runs fine on regular and doesn't have anything to gain by higher octane fuel if pinging/knocking is not present.
C//
I just thought the H-6's just didn't have low rpm power... Learning new stuff everyday! /
Quite the opposite. For comparison, the one stock 2.5 turbo I could find listed torque at 2200rpm at about 60 ft lbs.
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Dont know how I originally missed this thread. First thing to do for the gear hunting is a tcu reset. That can be done with a vagcom cable, a laptop, and freessm. As for the soft shifts, the 05-07 5eat's have a couple of valve body mod options. Transgo 5eat 350z kit installed by a transmission shop or yourself if you're nuts, or the hexmods vb. Look into them on legacygt.com if youre interested.

You should definitely start off with a tcu reset.
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