2013 Prius c Software Bug

Hey everyone, first post here. I joined the forums to see if anyone else is experiencing the same intermittent issue I'm experiencing. It's only happened about once per month that I've owned the vehicle, which is about 4 months.

For background, I'll cover normal operation of the Prius c. Let's assume the ICE is warm and the vehicle is at a stop. Therefore the ICE is off. When you begin accelerating from the stop, the car only uses electric power to accelerate. When you begin accelerating at a high enough rate (past the ECO line), the ICE will kick in and accelerate the car for you. Whenever the ICE kicks in, the EV light will turn off signifying that you are no longer in EV mode and that the ICE is running. I know that the EV light is different from the EV button. I almost never use the EV button, so it has nothing to do with the problem.

The problem I've been experiencing is similar to the scenario above. The vehicle is warm, you're at a stop, and the ICE is off. I will begin accelerating using only the electric motor. However, when I pass the ECO line (when the ICE should kick in), the EV light will turn off as if the ICE is on, but the ICE never turns on. The vehicle continues to use the electric motor no matter how hard or lightly you press the gas pedal. When I accelerate more, I can hear the electric motor really start to spin up and put out some power. That's what alerted me the first time it happened. The thing sounds like a jet taking off.

I think the first 2 times, I just let off the gas, got back on it, and the ICE kicked in like it should have. The other times, I tried the previous trick, it didn't work, then I had to stop the vehicle and start again to get the ICE to kick in.

When I'm in this situation and accelerating rapidly with only the ICE, I can actively watch the battery level go down. It only takes a second or two for the battery to go down an entire bar. The first time this happened, the battery dropped to just 1 bar in less than ten seconds.

So, let me know if anyone else has been experiencing this. I really think it's a bug with the software controlling the hybrid system.

 

Don't know. I've tried slowing down, then accelerating again and the ICE still doesn't want to come on. I'd say the longest it has stayed in the malfunctioned state is about 20 seconds. After that time, the ICE never came on but the battery was running very low, so I would stop the car and start again.

I'd like to drive it in the malfunctioned state until the battery runs out (or the ICE might come on), but I just don't want to break my only mode of transportation, even if it's under warranty.

 

I seriously doubt it. I think the closest I can get is recording everything and waiting for it to occur.

 

Chris:
I don't think I ever got over 45 mph. I would always slow down and try to correct the problem by then. I'll push the vehicle next time to see what happens.

X:
I'm sure it's the electric motor I'm hearing and not the ICE.
What do you mean by SG? Is that some sort of OBDII scan tool? I'm not using any type of OBDII interface right now, though I'm thinking of picking up one and logging all data on the vehicle's data bus to see if it's trackable that way.

 

Nope. Don't have one. I'll definitely look into getting one though.

 

Sounds like I need a Scan Gauge so that I can log Engine RPM vs vehicle speed vs Electric Motor RPM. I don't now if I can get the electric motor rpm, but I'll look into it.

If I can get a log of data showing an ICE RPM of 0 at 50 mph, I think that should prove the bug because the ICE should never be off > 45mph. It should just idle, right?

 

Right, but I believe the with the bug, the EV light turns off below 45mph and the engine never comes on.

 

I would think it's a bug. The engine is supposed to be on and it isn't. I've never had the stones to really get up to speed in the 'bugged' state, so I don't know for sure if it will cause a problem. I've always been reluctant to possibly damage my hybrid system.

 

Nah, I don't quite think so. It sounds like your EV light is on and that the electric motor is REV limited rather than speed limited, so it's able to go a little bit further than on a level plane.

Anyway, I just bought a bluetooth OBDII adapter and bought Torque Pro for my Android phone. Now my phone logs the RPM, Speed, Throttle Posistion, and GPS Data twice a second. If the bug happens again, I'm pretty sure that'll catch it.

Speaking of OBDII, does anyone know the PID to get the Hybrid Battery Charge. I could really use that, but Torque doesn't know the PID for it.