bdecriscio Posted August 19, 2005 Share Posted August 19, 2005 My 1999 outback wagon(auto) downshifts from 4th to 3rd whenever I go down a relativly long hill. This occurs w/o any input from me and it it reluctent to upshift back into 4th. untill I slow down and go through all the normal upshifts. I had it checked at a trans. shop and no error codes appeared. Other subaru owners have told me this is not normal behavior but I'm not sure where to go next. Any help would be appreciated, Bob Quote Link to comment Share on other sites More sharing options...
nipper Posted August 20, 2005 Share Posted August 20, 2005 Im not sure how the auto tranny on the 99 decides to shift. A tranny if it is not too computer controled, justifies shift points by balancing govenor pressure vs throttle pressure if i remember correctly. Govenor pressure is the speed of the output shaft, throttle pressure is sourced either by a vacumme signal, electrical signal from the computer, or mechanical connection from the gas pedal. For it to downshift going downhill, means either the govenor is loosing pressure, or the throttle circuit is gaining pressure. It is a balancing act between the two pressures. A good transmission shop should be able to put gauges on the trransmission to see the two pressures and see whats going on, assuming there are pressure gauge taps. nipper Quote Link to comment Share on other sites More sharing options...
MiniTransAm Posted August 20, 2005 Share Posted August 20, 2005 My 99 OBW does that as well. But it will only do it when I hit the brakes. Could be some kind of system that helps with downhill braking. I haven't thought much of it. Quote Link to comment Share on other sites More sharing options...
nipper Posted August 20, 2005 Share Posted August 20, 2005 could be but I havent read anything about it. Is it the lock up torque converter disengaguing or an actual down shift? nipper Quote Link to comment Share on other sites More sharing options...
ccrinc Posted August 20, 2005 Share Posted August 20, 2005 It's an actual downshift. The Phase II 4EAT tranny has all kinds of "new" modes, all computer controlled. IMHO, it's because a lot of people have no idea about "engine braking" and will wear out/overheat their brakes riding them down a long hill. Frankly, the Phase II is a nightmare inside, so take good care of it! Emily http://www.ccrengines.com Quote Link to comment Share on other sites More sharing options...
Commuter Posted August 20, 2005 Share Posted August 20, 2005 It's an actual downshift. The Phase II 4EAT tranny has all kinds of "new" modes, all computer controlled. IMHO, it's because a lot of people have no idea about "engine braking" and will wear out/overheat their brakes riding them down a long hill. Frankly, the Phase II is a nightmare inside, so take good care of it! Emily http://www.ccrengines.com Emily, when did the "Phase II" 4EAT come into being? I have a 97 OB. Commuter Quote Link to comment Share on other sites More sharing options...
ccrinc Posted August 21, 2005 Share Posted August 21, 2005 The first Phase II trannies were in some of the '99 models. Most came into use in 2000. Emily http://www.ccrengines.com Quote Link to comment Share on other sites More sharing options...
MiniTransAm Posted August 21, 2005 Share Posted August 21, 2005 Yeah it's an actual downshift. The rpms jump up and the front of the car sits down a bit. Just like a downshift on a manual car. Quote Link to comment Share on other sites More sharing options...
bdecriscio Posted August 21, 2005 Author Share Posted August 21, 2005 Hi people, I think I'm seeeing that my downshifts are something normal that is generated by the computer but I'd like to be sure, It does seem logical to aide in slowing but it's somewhat annoying in light of gas prices to be always lowering gears. I live in a very hilly area of the country and it seems like I should be able to upshift a little more easily by increasing gas input or something to return to a higher gear. I appreciate all the input in this thread and anyone knowing for sure that I'm not dealing with an isolated problem your help is greatly appreciated Quote Link to comment Share on other sites More sharing options...
sea#3 Posted August 22, 2005 Share Posted August 22, 2005 This might explain things http://endwrench.com/images/pdfs/19994EATInfo.pdf SEA#3 Quote Link to comment Share on other sites More sharing options...
friendly_jacek Posted August 22, 2005 Share Posted August 22, 2005 sea#3, good find. the article clearly explains that the downshift is triggered by brake and released by acceleration. maybe your TPS is malfunctioning if it still downshifts while you are adding gas? Quote Link to comment Share on other sites More sharing options...
bdecriscio Posted August 22, 2005 Author Share Posted August 22, 2005 Thanks!, I think I may have a problem with the tps but i'm relieved to know the behavior is normal. Great info from all you guys and gals. Bob Quote Link to comment Share on other sites More sharing options...
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