I have a 2000 Outback Automatic transmission that shifts hard between first & second about 50% of the time. 100k on vehicle, fluid & screen just changed. Any idea what to look for?

Hi and welcome,

 

Before you do any of the below: Any CEL or AT Temp Light (not sure if the '00 OB has that still) on?

 

What does it idle @ when warmed up? I'ver read that a TPS (throttle position sensor) or IACV (idle air control valve) can cause weird shifts, too.

 

How many miles since the ATF and Screen were changed? It takes the TCU/TCM (trans control unit/module) a few miles to 'relearn' the shifting if your fluid was bad enough to cause the poor shifting....also, you can try 'resetting' the TCU / ECU (engine control unit) by disconnecting the Neg. battery terminal for an hour (remember, you'll lose your radio presets AND your remote key fob/alarm may need 'paired'  - so know what needs done b4 you disconnect!).

 

Your car will 'start from scratch' as both computers (Trans and engine) relearn their jobs...but if it won't fix any existing issues, as they'll eventually come back.

 

GL,

Td

Edited August 29, 20169 yr by wtdash

^^ good post. batt disconn. trick cured high-speed hard downshifting on our last road trip. 

 

Some folks have cured delayed shifting with Trans-X additive - you might consider it if you do any fluid changing.

 

Uh - did your car get a timing belt system service yet? It's WAY overdue if it was never done.

Edited August 29, 20169 yr by 1 Lucky Texan

Where is the TCU/TCM located?

The TCU/TCM is located underneath the dash on the left side of the steering column.  I have a 2000 Outback, also, and our models are equipped with a 4EAT transmission, if yours is an automatic.  The transmissions in the Legacy, Outback, and Foresters made in 1999 and 2000 have a bit of a problem.  Its only these two years that have the notorious "Subaru Delayed Forward Engagement" issue, which has been dealt with in depth on this website forum.  If you will check the forum, there is a cure.  In short, the cure is to replace your transmission fluid with Valvoline Max Life Full Synthetic Multi=vehicle ATF Dex/Merc: Mercon LV Automatic Transmission Fluid with a pint of Trans-X Transmission fluid (found at NAPA and AutoZone stores.  There are a couple of seals deep in the transmission that begin to fail, and the Trans-X seems to cure the problem!  It costs around $12, and works well if you use it with every transmission fluid change every 30,000 miles.  To me, I would rather pay $12 for the transmission additive, than $4500 for a new transmission, or $2100 for a transmission re-build.  Your vehicle with 100K miles should have cost in the $4500-$5000 range so the cost of a new or rebuilt transmission would seem to pretty high.  The transmissions are really well built, and there is nothing wrong with them except for those stupid little seals.  If you do need a TCU/TCM, a new one will be around $450, but I may have a pre-owned one for the 2000 model Outback for $50, if I can find it.  At any rate, good luck.