Apparently about 3500 '04s have some part of the ECU that may be erratic and should be replaced. Otherwise the ECU goes into a "safe mode" and the car runs jerkily. Today I called Toyota support (800-331-4331) and was informed that my car was indeed one of these 3500 and they will now arrange with my local dealer (SF Toyota) to have me bring the car in for a 2-hour repair/upgrade job.
There's a discussion on it here, actually and I've posted the notice in the File Library for archive purposes.
I recieved a letter from Toyota Motor Sales in San Diego last week about SSC 40A- 2004 Toyota Prius hybrid vehicle electronic control unit reprogramming. Called Lithia Toyota in Medford and they did their thing with the ECU in about 45 min. On work order it says " re-calibrate HU ECU". prius
Has anybody on this forum ever had the problem that is supposed to be fixed by the sc-40a recall? The reason I ask is that a couple of weeks after I took delivery of my car I drove it nearly 2000 miles on a trip to Florida. When I got there, I changed the oil and filter. When I restarted the car for the first time, I got a master warning and a check engine light. Everything seemed OK----full oil, pre-filled filter, no leaks. Backed out of the garage, everything normal except I had the check engine light. On the next restart, everything that could go wrong did. The car barely moved. The ICE would not start and the car ran in electric only mode. Finally the engine started but ran at an extremely high rpm. Each restart ended with the same problems coming back. The nearest dealer was over 50 miles away and since this was my only car, I disconnected the battery to clear any soft codes set in the computers. The car then restarted normally and has since then (another 3000 miles). My car is in the VIN range of those needing the code update but the sticker on the hood and a check with Toyota says that the modification was done at the port when the car was shipped into the country. Not a real problem as it seems to be reset by disconnecting the battery---but a concern anyway.