I have a 2000 Outback with automatic, 125K miles, that suddenly developed a shift problem that slams the trans into the next gear and only when the engine is rev'd up to 3500 to 4000 rpm. Otherwise the car will not shift gears. It downshifts automatically as you come to a stop o.k. but will not change to the next higher gear when accelerating until those high revs and then bangs into the next gear with huge jerk. Will not shift to fourth until car is doing over 55 mph and again it does that with huge jolt. Backing off of the gas to help it shift has no effect. Is this a control unit problem, a mechanical problem, where is the TCU located for this car and how are the codes indicated and read? Thanks for any help......

I have a 2000 Outback with automatic, 125K miles, that suddenly developed a shift problem that slams the trans into the next gear and only when the engine is rev'd up to 3500 to 4000 rpm. Otherwise the car will not shift gears. It downshifts automatically as you come to a stop o.k. but will not change to the next higher gear when accelerating until those high revs and then bangs into the next gear with huge jerk. Will not shift to fourth until car is doing over 55 mph and again it does that with huge jolt. Backing off of the gas to help it shift has no effect. Is this a control unit problem, a mechanical problem, where is the TCU located for this car and how are the codes indicated and read? Thanks for any help......

 

Did you change the fluid and filter and whatnot?

Is the engine light and/or AT temp light on or blinking?

I had these same symptoms with TPS failure when TCU "assumed" that throtle was wide open all the time.

However, both ECU and TCU reported codes for TPS problems.

CCR engines reports problem with tranny computer. Perhaps Emily can explain it for us of the lumpen proletariat.

I am driving with the second replacement tranny for my 2000 Legacy GT!

First one had delayed engagement and he second one developed a ticking sound in P and N.

Is the engine light and/or AT temp light on or blinking?

I had these same symptoms with TPS failure when TCU "assumed" that throtle was wide open all the time. However, both ECU and TCU reported codes for TPS problems.

 

 

Thanks for the response. No check engine light on and the AT temp light is not on or blinking. Did changing out the TPS fix the problem? I will be changing the trans fluid, pull the pan off and check to see if any nuts and bolts are floating around, but sounds like it is a control problem. I'll check connectors and see if anything changes. The closest Subaru dealers are about 5 hours and 250 miles from here so I prefer to figure it out myself whenever possible.

Does it shift OK manually? If so, maybe the TCU or ECU. Sure would be nice to go back to the simple life of a vacuum modulator instead of an array of solenoids.

Thanks for the response. No check engine light on and the AT temp light is not on or blinking. Did changing out the TPS fix the problem?

 

Yes, TPS had to be replaced ($300 outch!).

Go ahead and test yours with a simple resistance meter, it should behave like your typical potentiometer. If it's good, then who knows, need to do extended diagnostics, hope you have a factory manual.