Hello All, ECU IG fuse & IG2 fuse block: Putting 12v to it starts dash lights and the lights start blinking But key press doesn't start car Where does the power to the transmission computer come from? HV ECU... no power Transmission ECU... no power ECU IG fuse... no power Can't read codes from the above ECUs, only the body ECU and it gives codes B2287 & B2289. I replaced the PSC ECU and the car started once. Now any replacements don't start the car. Wires and fuses are fine. Relays may all be fine. They work and were checked and swapped and still work.
Where does the power to the transmission computer come from? A fuse under the hood. I went through similar and replaced the powertrain control module (next to the engine ecu behind glovebox) only to find a road salt destroyed fuse that went to the ptcm In my case there were no codes, no ready, shifting it placed it in nuetral only.
Thank you @tracy ing . If I unplug every ECU near the dash/driver side/passenger side so that means the Transmission, Gateway, HV Control, Power Source, Smart Key, etc and then plug them all back in the car starts and will go into ready. Addition: I don't have to press the "Start" button after plugging in the last ECU. The car just jolts on after the last ECU is plugged in. Then, if it sits off overnight, I can't turn on the car anymore.
Also, if I'm using Techstream to read codes after an overnight period where in the morning the car doesn't start, I'll do a health check and only get some ECUs. If I unplug an ECU that doesn't show up and then plug it back in and then do another health check then that ECU will show up. So the ECU show up once plugged in and unplugged.
Are you plugging them in with the low voltage battery connected to the car ? If so, probably shouldn't be doing that. Aside from possibly damaging something, i would think that would create codes as this doesn't see that on unit boot up
If you handed me that car, the first thing I would do is use the CHEAT to reprogram any new devices, like when I added that EBAY powertrain control module, that would not work because the car didn't recognize it, authorize it. I dont remember the exact process, but is starts with, get a good car battery and jump it to your battery to your battery does not die during the process. (a battery charger may add problems so I use a good big battery). Then you do the process which I think was press Power and walk away for 30 minutes, someone here can correct me and tell you the right way. I would do this first because I don't know what is going on in the car at this point and I want to discount this as an issue with any replaced electronics. Before I did that, I would try to find every connector someone may have fiddled with an unplug and reseat them, with the low voltage disconnected. And before I did that, I would check every fuse in the car lol.
The same symptoms i saw today in 2009 prius. The instrument cluster went blank and the owner started checking all the fuses, after which the car stopped starting. The power button didn't glow in any color at all. The shop checked the fuses under the dash, but did not check the fuses in the engine compartment and called me. When I checked the fuses in the engine compartment, the fuse "p con main" (Parking control system, 7.5amp) was missing. I haven't checked wiring diagram what it powers, but the website startmycar.com/us/toyota/prius/info/fusebox/2007 says that it also powers the transponder key ecu. In my case, I think the following happened: the missing fuse interrupted the power supply to the transponder key ecu/id box, which is located behind the hvac box and the power source ecu did not receive a response from the transponder key ecu via the LIN bus and the power source ecu did not load. The repair shop was able to connect to several computers (I don't remember exactly which ones), but the transponder key ecu failed to connect. They were able to pull these 2 codes. B2287 - LIN COMMUNICATION MASTER MALFUNCTION B2289 - KEY COLLATION WAITING TIME OVER The Toyota repair manual says that these codes triggered when the connection/communication between power source ecu and transponder key ecu is abnormal https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/repair%20manual/04pruisr/05/21bi6/cib2287.pdf Based on my experience with the Toyota Avalon, which I recently diagnosed with the same symptoms, where the transponder key ecu failed and the car showed no signs of life. Prius may have the same problem.
So for your 2009, did replacing the p-con fuse fix all of its problems? Someone is leaving out details somewhere, as I have never seen a fault WITH THE CAR cause a fuse to remove itself from a fusebox. Posted via the PriusChat mobile app.
