I recently purchased a 2010 Prius with 60kmls. The car looks nice on the inside and out. Where i live there is no Prius specialist. from what i heard the car wouldn't start. They tried a lot of things without proper knowledge and tools, including scan tool. The car has a lot of mechanical problem. - missing hybrid battery, abs module and pump,water-pump (solved) I have 2 main problems remaining When scanning the car the scan-tool doesn't find the Transmission control unit and The security light keeps blinking even after ignition is turned on. When i press the brake the ignition light turns green. When i put the car in neutral the display shows neutral but it doesn't actually go in neutral. The car still doesn't start. Could a faulty TCU cause this no start?
The "transmission control unit" in a Prius is a grandiose name for the ECU that controls the little motor that shifts the transmission in and out of Park. So if there's no communication with the TCU, and the car still seems parked after selecting neutral, that's not too surprising.
Thank you for the clarity on the purpose of the TCU. I took the TCU out and opened it. Seems like water was in it. Corrosion on the connector pins and also on the circuit board. I ordered a used part but will have to wait for about 2 weeks before i receive it. I have uploaded a file with the faultcodes. Can you be so kind to see if there are more modules missing. Can the missing TCU be the reason why the car does not go to ready or the brake fault? the car was brought to me on a tow truck and can't easily be moved now. i was hoping on fixing the out of park problem first and go the other items such as brakes. I have a lift which will work much easier
It looks like there are other problems besides the TCU. The brake system codes appear to be about legit brake system issues. I'd say your plan is sensible to work on other issues once you can get it out of Park and roll it around. When replacing the transmission control ECU, I would want to check the Repair Manual carefully for any extra steps needed. Because the Prius does not have a steering column lock and the transmission control ECU and parking actuator are considered to be an equivalent anti-theft measure, the transmission control ECU does communicate with the certification ECU to make sure a recognized key fob is detected. It is possible that a special pairing step could be needed when either of those ECUs gets replaced. There is a large PDF of the 2010 Repair Manual that kind of floats around the net, but it's not 100% complete, and I was not able to find the specific transmission control ECU replacement instructions in it. I would probably check for those in an official version of the manual: Toyota Service Information and Where To Find It | PriusChat
