Hello! 2010 Prius with 180k miles. Completed a tuneup, car started and drove smoothly for 3-4 days. Gas mileage went up from 28 to 44mpg. On a short trip at 12-15mph, the car revved like it slipped out of gear. I pulled over immediately, checked under the hood, nothing was leaking and everything seems connected. Received yellow triangle along with "Check Hybrid System." Looked up codes with OBD2 which are P0335 & P0102. Engine does not start, cleared codes and tried again but same thing occurs on start. Tune-up included: -Cleaning intake manifold -Cleaning throttle body -Replace PCV -Cleaning MAF -Replacing Spark Plugs -Cleaning EGR pipe and cooler -Replacing air filter -Cleaning HV battery fan (after car received the triangle) All items that were cleaned were VERY gunked up. Is it possible the current state of the vehicle is related to the drastic changes that occured after tune up, like the ECU/ECM is receiving very different input than it is used to? I (think) I noticed the ICE was shutting off more frequently at stops than it was prior to tune up. According to the hybrid assistant app, the state of charge for the HV battery is 28%. The 12V battery was replaced with a new one, 2 months ago. I have read that checking the crankshaft position sensor and plug, then checking the wiring harness that connects it to the ECU is the way to go. I am a relative novice in regards to mechanic work but it seems that replacing the crankshaft position sensor is relatively doable, I will have to look into how to check the wiring harness. Is this the path forward? Should I invest in a mini VCI to gather further information on the vehicle? Just trying to figure out at what point I tow the car to the shop. Thank you in advance for your feedback!
Did you disconnect/reset the 12v after the tune up? Had you not had 3-4 days of trouble-free driving prior to error codes I'd point you to loose connection when putting car back together. If you have a friend with a Prius you could borrow their position sensor and MAF sensor to confirm that's the problem.
I'll check out maf sensor and wiring. Would this be related to the crankshaft position sensor error? Or are these completely independent issues? I had initially forgot to plug in the MAF sensor after tuneup and the car started totally fine. I did plug it in shortly after.
sometimes one thing leads to another, sometimes not. that's the only related thing i can see that you did during the tune up. if you can get that fixed and it still won't start, maybe you need a new sensor, or there is wiring corrosion there.
i have never heard that sound before, but i have never heard a prius trying to start without starting. are you still at 28%? how many battery bars? maybe it cannot start if the crankshaft is in the wrong place
