JimFierst

Thank you very much...I did have the motor mounts looked at last week when I had the half shafts and O2 sensors replaced. It was not a dealer so perhaps he did not know what to look for. I have an appointment with a dealer in CA this coming week and will request both of those be checked.

The idle is normally very smooth . I just cleaned thew throttle body and valve .Plugs about 12K ago. It only happens when the car is stopped and the brake is depressed It tends to be even. I don't see how it could be tires brakes or axles.. Again and for one last time I will ask the question, Can a dealer run some sort of diagnostic program on the TCU.

Thanks for the post.Way too complicated for me.. . I am trying to identify the source or cause of a transmission shudder/vibration problem.2000 Legacy OB,112K miles The idle is set at about 6 to 700 RPM and is smooth. When the trans is placed into gear or comes to a stop in gear the vehicle wants to move forward and must be held with the brake,. After a few seconds the trans begins to shudder . It seems like what ever senses engine rpm and feeds the TCU data is sending bad data or the trans is responding incorrectly. Can a dealer run a set of diagnostic tests on the TCU??

Is there anywhere on line I could look at a description of the functions of the TCU for a 2000 legacy Outback.? I am looking to get the source of the TCU's inputs and the action it takes. I am aware that the TPS sends throttle positions and the TCU causes up shifts and down shifts.

Thanks for the explanation of the first 2.. I am familiar with TPS having one in an older Bosch system.If the TPS was reading a higher than actual idle would the ECU or what ever cause the transmission to try to engage . The problem I actually have is the transmission engaging with the idle down around 600 or so. I get a shuttering when I hold my foot on the pedal. When I release it the car moves slowly ahead. When I move it to neutral there is no change in RPM. Any thoughts

On my 2000 Legacy Outback wagon there is a valve ? of sorts that feeds mixture in after the throttle plate. I had it apart to clean when cleaning the throttlr body. Further down stream is another electrical connect to some sensor bolted in the plenum. 3 qUestions What are they called? What do the do? Do either have any interaction with the transmission in any way? TIA Jim

Just to wrap up this thread... I rechecked the idle speed and it is on the second mark and assuming the 1000 rpm range is divided in thirds it is at 660 RPM. More inportantly i found a deserted street where I could go from stopped in neutral to forward or reverse .Itested moving the selecter into gear without doing anything else . The car moved forward or reverse with no hesitation vibration or shudder. I am saisfied that the problem is idle speed related and will find a way to get it looked at at a dealer. Again thanks to all. If you ever get in to Fiats or Lancias look me up at my web site www.whoabrakes.com

Getting back to everyone.. !. If the thread was among the 16 pages of posts I looked at I missed it. 2. Idle speed is 750 3. I do not use the defroster and the heater control is set on the floor.Changing it just now makes no difference. 4. The condition get a little worse with the a/c on as the idle goes up 50 rpm or so. 5. I just had both half shafts replaced with aftermarket assemblies and both O2 sensors replaced at the same time. 6. I had the motor mounts inspected at that time. 7. Plug wires have not been replaced. A local shop seems to think that cleaning the injectors and fuel delivers system will make a difference but I am rejecting that. Any other thoughts ? Jim

I spent the last hour+ combing the 16 pages of posts for this problem and did not find it. The vehicle is a 2000 Outback wagon with 114,000 miles. The trans had the fluid and filter changed at 50 & 100K. The vehicle has never been overloaded ofr used for towing. The problem is as follows; When sitting in gear when idling at a stop there appears to be a shudder or vibration coming from the trans . If i move the gear selector to neutral it stops and when I move it to drive or reverse it starts again. The problem is much worse when cold and sometimes is not very noticible after driving a while. When warm if I stop and select neutral then and reselect drive or reverse it will do the shudder or vibrate. Anyone know the cause of this ? I am locarted in a city with out a Subaru dealer and am hesitant to take it any where else for diagnostics. TIA E-mail me direct.Jim fierstja@frontiernet.net