drives me crazy

[Patrick Wong]

Originally Posted by tomfreed

P3120 is the only one shown at this point, i have the engine light and the triangle symbol on the console, i can't retrieve the 3 digit info. code, car can be driven and it drives quite normally with normal power, no noise, shut off just fine.

Can you provide the electrical diagram for all connections that goes to the tranny? i have to ohms it out to see if i have any broken wire internally that keeps giving me this error

I got rid of my Classic technical manuals when I sold my 2001, but you can download the Electrical Wiring Diagram for your model year for $15, from techinfo.toyota.com which is a subscription website. That fee provides two-business-day access to the website.

It's interesting that you are seeing the check engine light appear, since DTC P3120 is supposed to relate to the transaxle. If the check engine light is on that would imply an engine-related DTC logged by the engine ECU (aka ECM.)

If the car can be driven normally, then it would seem that the transaxle and inverter are fine and that DTC P3120 is an artifact, probably due to a bad connection. Although it would be interesting to track that down, its not the end of the world if you can't figure it out - unless your objective is to sell the car and you can't sell while warning lights remain on.

It sounds like you've developed tremendous hands-on experience with Classic models; good luck figuring out this thorny problem.

[tomfreed]

Originally Posted by Patrick Wong

I got rid of my Classic technical manuals when I sold my 2001, but you can download the Electrical Wiring Diagram for your model year for $15, from techinfo.toyota.com which is a subscription website. That fee provides two-business-day access to the website.

It's interesting that you are seeing the check engine light appear, since DTC P3120 is supposed to relate to the transaxle. If the check engine light is on that would imply an engine-related DTC logged by the engine ECU (aka ECM.)

If the car can be driven normally, then it would seem that the transaxle and inverter are fine and that DTC P3120 is an artifact, probably due to a bad connection. Although it would be interesting to track that down, its not the end of the world if you can't figure it out - unless your objective is to sell the car and you can't sell while warning lights remain on.

It sounds like you've developed tremendous hands-on experience with Classic models; good luck figuring out this thorny problem.

I took the car to Toyota dealer last year twice already for $90 a pop diagnosis only. I got pissed off still not working I did not do anything afterward but now it began to get on my nerd with thousand of dollars in parts, labor, time, hair pulling, cussing and the car is taking up space in my garage and is becoming an eye sore. I really hate 01-03 Prius and will never buy another one.

It is uncertain that the car is driving fine on freeway and every day use as i only drove around the block after putting in the third transmission. With the pictures i attached how much do you think i spent on expensive parts just to have the car still not fixed. Yes I can't resell the car with engine light on at both locations on console and on the dash.