violent shaking at start up

Several other owners have posted about this, so yes, it has happened to others. So far the cause remains unknown.

Search is a useful feature.

Tom

 

It sounds like you've got a conflict between the gasoline engine and MG1. When the hybrid vehicle ECU is starting up the engine, MG1 serves as a starter motor to spin up the engine. Once the engine starts then MG1 should continue to spin at an appropriate RPM so that the engine can idle.

Since you're experiencing this severe vibration, it appears that MG1 is not spinning at an appropriate speed, hence it is fighting the engine.

This happened once in a while with my 2001, when coming to a stop. It seemed that disconnecting the 12V battery to reset the ECUs helped. I did not notice this problem at all with my 2004.

Suggest that you document the problem with a video camera, next time it happens, so that you have evidence to provide your dealer. (I assume that no warning lights have appeared.) However, until a TSB is issued its unlikely that they'll be able to do much for you as a permanent fix would require new firmware for the hybrid vehicle ECU.

As an early adopter of the 3G Prius, I'm sure that you'll notice occasional glitches from time to time.

 

This has happened to me once with my 08 when it was pretty new. Never happened again, I just chalked it up to, one of those things. Sorry to hear your Prius continues to dissapoint you. Why do you say that?

 

The rather severe shaking on start up has happened to me twice now. Both times with a cold engine. Seems to last about 5 to 10 seconds. No solution yet and Toyota denies the problem exists, as usual. Here is the thread:
http://priuschat.com/forums/gen-iii...troubleshooting/70128-rough-engine-start.html

 

Take a look at this thread:

http://priuschat.com/forums/gen-iii...troubleshooting/70128-rough-engine-start.html

Tom

 

I'll just say real quick that it happened to me once this summer. It has not happen since and yesterday it was 0 degrees here. I don't think cold temps have anything to do with it but that is just my opinion.

Peter

 

The one thing that seems consistent is short engine runs and then on later re-start it occurs. Maybe we have found a real use for EV mode?

 

Was this your First start of the day or had you run the car before this rough start occurred?

 

I got the shake the other day but under different circumstances. It so happened that it was morning and I turned the car on, put it in reverse, backed-up and put it in neutral at the exact same time the engine was starting up. Neutral won out and the engine went immediately back off again and the car shook when this happend. Even more strange, as I put it in drive to go forward, I was able to stay in stealth mode and the engine never started up again. This was a cold engine!! It should've started as I drove forward under power but it didn't. Thinking I might've broke something or blew the electronics mind, I parked it, shut it off completely, waited a few seconds, then turned it back on again to find the ICE starting up normally and the car drove fine.

 

Is this a 2009 Prius as shown in your profile? If so, note that this thread relates to the 2010 Prius. The Gen II Prius don't suffer from the same startup shakes as the Gen III, so it might be similar but not the same problem.

Tom

 

The hybrid transaxle motors play a part in both starting and stopping the engine. By shifting into neutral, they can't finish their part and that leads to hearing and feeling rough engine operation. Keep it in gear a bit longer and life should be good. But since you have a 1.5L engine, you might consider cleaning the throttle area.

Bob Wilson

 

Thanks qbee... I knew this was the 2010 area but just wanted to comment on the thread with a similar experience. Or because I own a GenII I'm banned from posting here? Hope not.

 

Not a problem. I just wanted to make sure that you and other readers realized that these were unrelated issues. Granted, they both involve rough engine starting, but the root cause is not at all the same.

Tom

 

Sure. I appreciate your candor.

 

This definitely appears to be related to short cycle running of the ICE.

I don't really think it's an issue but what I do is at least let it run until the first shut off, and I have not experienced it when doing that.

It's only a matter of a minute or so...so worth a try to see if that helps eliminate the recurrence.

 

It will be interesting if this issue pops up after say 10,000+ miles. Perhaps the system just needs to loosen up?