Hey Y'all -

 

First post here - I used to hang out on the "older" side when I ran GLs, but I took a leap and picked up a 91 legacy turbo, and almost immediately started having issues with it dropping out of overdrive on the highway. RPMs jump up, "power" light comes on, then it kicks back to normal.

 

It has what appears to be an overdrive overide at the base of the shifter by the gear indicator panel, an I right about that? I pushed it, no light or indicator to tell me it was doing anything...is it possible that swich is bad or something? Any thoughts are much appreciated!

 

R

Hi Rev. I could be waayyy out on a limb on this one but I think possibly a bad/dirty TPS could cause this issue. The power light comes on when the TCU switches to 'power mode', which basically happens when you press down on the throttle fast enough (rate of change). So if you're cruising along at say 20% throttle and that happens to be bad spot on the TPS and say then the TPS tells the TCU you're now running at 60% throttle that might be enough to make it go to power mode and downshift for a split second.

 

Anway there are excellent detailed articles about how it all works for the phase I 4eat on http://www.endwrench.com just click archives and search for 4eat.

The interlock release lever switch by the panel allows the shifter to move w/out the key inserted. There is no overdrive override switch...shifter must be moved to 3rd.

 

If the 'power' light comes on, their may be a code stored. Check this:

http://www.surrealmirage.com/subaru/trans.html

Thanks Homeys!

 

I ran the diagnostics suggested by Mr. WTDash - "current problems" mode flashed continually (don't know what that means - off to do more web crawling), "previous problems" flashed 3 long, 2 short, 3 long, 3 short - 32,33, as I understand it (this is all new to a cave dweller such as myself) which according to the chart is vehicle speed sensors? How does this fit in with Mr. Porcupines theory?

 

But get this - I took it out and beat it a little bit, and it didn't do it (no drop out of od, no power light flashing on) - possibly dirty sensors from sitting in all summer? The dude who had it before me didn't drive it much in the last year.

 

Regardless, I appreciate the feedback. I'm a little warry of these new (less than 20 yr old) scoobs, but I decided to give it a go - one thing is for sure - this thing don't run like a GL wagon! Scarey quick!

hm...good diagnostic work. You can probably ignore my long shot hunch since you have codes to work with. There's a good articles on endwrench.com for the 4eat phase I. Yes those early 2.2L Legacies are pretty quick, maybe it was before the ODBII emissions requirements or something. Make it a turbo and fllllyyyyyy

Speed sensors eh. Is your speedometer working??

yup - speedo is working -

Check the connectors on the transmission see if they are loose or maybe the contacts are dirty?? But the connectors are sealed so pretty unlikely. I am guessing its AWD correct?? On the back of the transmission there is a speed sensor. You can remove it and see if its dirty or rusted or something like that. There is another speed sensor behind the guage cluster which uses the speedometer to determine the input a signal as a speed sensor as well.

Thanks!

 

Hmmm, that's interesting - the day it started acting up, I did hear a weird noise from the dash behind the speedo - I thought it was just a rattle and I gave it the good ol' fonzie fist and it stopped- maybe I knocked a sensor loose? or maybe was a symptom of an exisitng problem...

Oh yeah, btw, it is AWD

RE: the codes:

 

"Blinking once every 1/4sec is normal"...meaning no issues.

 

Sounds fixed?

 

Good luck.

Hmmm - could be! I'll let you know after I take it on the highway today - thanks for the edgey-ma-kay-shun!

I have the same car. VNRS : Very Nice Rare Sedan.

 

The VSS #2 (vehicle speed sensor) is located in the speedometer head unit.

If the speedometer cable binds due to lack of lube

it could cause the noise and loss of the VSS #2 signal.

 

The other VSS (#1) is located on the tail shaft of the tranny.

 

 

Note to the Porcupine73: -- this is a turbo.

We both know these are also called SS, (Sport Sedan)

(if it's not a wagon)

it also

should have the viscous limited splip rear end.

 

Lots of good info can also be found at

http://bbs.legacycentral.org/

They specialize in this gen Legacy.

 

Best mod you can do aside from an IC is free up the

entire exhaust from the turbo back.

 

 

 

Hope this helps

here's mine

 

Note to the Porcupine73: -- this is a turbo.

hehe..sorry about that, I should start reading the post! Very sharp vehicle indeed nonetheless!

I smell dirty TPS. Dropping out of overdrive is almost always associated with a bad/dirty TPS. The VSS usually has nothing to do with it.

Thanks again for all the advice! It ran okay today - did about 70 miles on the interstate and in town. Is it possible that one of these sensors caught some junk and then cleared off? As I said, it hadn't been driven much for a while.

 

Maybe I'll pull out the tps over the weekend and take a look...

Ya, I guess you can clean it with contact cleaner? With mine I just realigned it. If when you are driving you are getting a random power light then must be the TPS as the power light when you are driving should only come on when you floor it. Here is how you setup the TPS according to the manual.

 

http://www.main.experiencetherave.com:8080/subaru_manual_scans/fsm_scans/tps_testing3.jpg

 

I did it made my car more responsive and shift better.