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
Once again thank you for the insight. What was a problem for me was the blinking security light. I assume that if the tcm is not working it might be seen as a fault in the theft deterrent system. Please bear with me. While waiting for the tcm there is not alot i can do. Hope you have a link to this post
Jeay, i received the TCM. Plugged it in and it worked right away. P came on, the scantool saw the TCM and no fault. Still no start. On the dash i see the notification "check hybrid system". The only fault i'm getting from the scantool is "P0A84 Hybrid Battery Pack Cooling Fan 1 Control Circuit Low". Indeed the fan does not work. I have about 6 fans used in the Prius C/Aqua but non for the Prius. What i noticed is that when i clear the fault code the triangle turn off and i see on the screen on the dash the car with battery level and the wheel. It stays on for a few seconds and goes back to the message check hybrid system. Could the fan be the reason for the car not starting?
A little bit of the history of the car. The car driven into deep water. Drove 2 days without a problem. After that it wouldn't start. They tried to get it running again but didn't succeed. The car was left. I purchased the car without battery pack, without abs module and pump. I had some spare parts from a CT200h. I was able to use the brake pump and module and also the battery pack. I realized today that i had purchased the new battery pack for the CT200h pack from the Netherlands. When i replaced the pack the CT200h also didn't want to start because of a different voltage module. I looked up what the number of my Prius should be and it differs from the one i have now. When i clear the fault codes i get this screen for about 5 seconds
Received the battery fan motor today. No more fault codes except for the ABS module. The triangle is gone but still no start. The faults still present are C1203 ECM/EV communication circuit C1242 Open circuit IG1/IG2 power source C1345 Linear solenoid valve offset I can hear that the relay module on the hybrid battery is not being activated. When i measure the current on the plug that activates the module there is no power on the wires. See the circled part in the picture. Tested the relays and all are working fine. Will a faulty ABS module prevent the car from starting. If i would disconnect it will it still start, turn to ready? Could a power management control module be faulty and not give a fault code?
