My Toyota Previa has a vibration when shifting into high gear,it is automatic transmision

SOURCE: 2005 Toyota Corolla with 36,000 miles Transmission now "jumps" into gears

hi,
when the check engine light comes on, your car goes into a mode where instead of everything being normal, things are forced, to try and compensate for something else being wrong. It most likely does need a new timing belt, and a complete tuneup INCLUDING plugs and wires. we have a 1984 toyota corolla and it purrs like ground rice, I suggest the tuneup to continue proper rice production.

J

SOURCE: Hello, I own a 93

The transmission is controlled by the Transmission Control Unit (TCU).

Throttle position, rpm, and speed are input parameters to the TCU. The TCU has a default set of shift patterns. These shift patterns change over time based on your specific vehicle setup and driving habbits.

The shift patterns are only slightly affected by driving habbits over many driving cycles. But, changing the relationship between the throttle position and the actual speed being reported by the speed sensor can have an immediate effect on shift patterns.

While your speedo may now be correct, the realtionship between rpm and thottle position has not been corrected. That would take a gear change in the differentials.

The TCU can be reset to an inital learn base line. When this is done, the TCU will instantly learn the dynamics of your setup.

Any shop with an advanced ODB scan tool can reset the the TCU. The dealer or a transmission shop would be preferable.

You really should change your differential gears as opposed to resetting the TCU

This information was posted by ftgiles here

mike kirschbaum

• 1198 Answers
• Posted on Jan 10, 2009

SOURCE: automatic transmission shifting problems

20 year old vacuum hoses are done. Replace all you can. The little plastic ones too. They control everything, transmission, computer, fuel, brakes, everything.

SOURCE: 91 Toyota Previa AWD - Swap original engine for Previa Supercharged engine

I do a lot of work on Toyota Previa before; including rebuilt engine, swapping engine and transmission and lot of things in between, but never swap a normal aspirated engine to a supercharged engine or diesel. Since i have some experience in Previa, I would like to share my opinion with you regarding your plan to swapping the normal aspirated Previa engine to a Supercharged engine. When you do a swapp like that, you will not only be dealing with just swapping engine, but some wiring, computer, throttle body, air cleaner assembly, extra frame and pulley on the accessory items, transmission as well as a right rear end to get the correct gear ratio to accomodate the new engine and transmission. I can go on even more, but let me tell you this, beside less headache, it would definitely cheaper if you were to find a Supercharged Previa and fix it up. However, if you are totally motivated to do this project, keep in mind, this engine swap will be a long term and time consuming project.l I wish you best of luck and have fun!

SOURCE: replace bulb on automatic gear shift console

If the shift console is on floor then look for bolts holding it down.  Take out bolts and then you can maneuver console so you can see where light is plugged in and get the right light to replace it.  It will probably be a small light which tend to cost a bit more, but at least you'll have the light back.