Hello:

Curious to you other NAH owners ever had this problem?

When braking (car transitioning to turning off engine often) the engine ends up revving pretty hard over and over for no apparent reason. I am concerned... just got the car monday and going out of town this weekend so I'll probably call service then... but wondering if anyone else had this problem. of note, it tends to happen in the first few minutes after I start the car, and then settles down.

That certainly sounds like a problem. The only odd things I have noticed in mine is that if driving on the highway for more than 33 minutes and then I exit and stop, the car enters EV mode and then shortly there after the engine comes on for absolutely no reason. The only other 'odd' thing is sometimes when transitioning into EV mode due to a complete stop the engine kinda has this choking sound (like if on a manual transmission if you release the clutch too fast on first gear, you choke your engine). This only happens when the car is cold though.

Any kind of high reving of the engine, doesn't seem to make sense as the recharge of the batteries is basically done at a fixed RPM (around 2K ish), so any reving higher than that calls for a checkup.

[edit]
Also (I just reread what you said), your car really isn't supposed to be entering EV mode in the first few minutes of operation as it is most likely still cold. Mine will enter EV @ 0mph after 3 minutes of operations, under 20 miles per hour after the first 5 minutes of warming up, ~35 after 10 mins, and it takes a good 15+ minutes before it will enter EV mode around 42mph which is the limit.

Zippy I have not experienced the racing engine situation you described. I have seen the engine jump out of EV mode while stopped at light (after highway driving) for no reason as Anton stated. I do have some questions, you stated "when braking" do you mean when braking aggressively or any kind of braking and occuring sometimes or all the time while braking? I have had non-hybrid vehicles which have accelerated while braking aggressively.

No it isn't an agressive braking, and it only happens occasionally (for some reason, not at all today). Another question (possibly related): I have the blue warning light on above the speedometer. In the manual this is the "cold engine light" as opposed to the "hot engine" light. Never seen that before in any other car.

Also, to go back to ILoveChess. When you say not entering EV mode during the first few minutes, surely you don't mean the engine kicks in while backing out of a parking space, right?

Here is typical of what happens. I work in a suburban office park. I back out of my parking space and the car is quiet as a mouse. As I give the car a little gas to go forward in the lot, the engine kicks on. Then I brake to stop at the driveway exiting the parking lot and the engine starts aggressively revving. What is interesting is that if I give the car some gas (a little bit aggressively) as I pull out, it usually takes care of the problem. Then sometimes, as I'll pull out onto the street and then stop in about 500 feet at a stoplight and it starts doing the revving again.

Lastly, I pulled up both the energy flow screen and the MPG (instant) screen when the revving happens. The energy flow screen does not acknowledge the engine providing power, but the MPG display shows fluctuation between 0 and 60 MPG. So there is that.

Zippy...you mean you never had a car with a temperature gage that showed the car as "C" for cold when you first turned over the engine? It is the same thing as the blue light. remember there is no Temp gauge in the NAH. The battery indicator replaces that so you just have blue for cold engine and red for hot. hope you never see the hot.

Also in cold weather, the engine will come on when you back out within a matter of seconds. That is not unusual. It is not coming on to move the car in reverse, but to get the cat converter warmed as soon as possible. This is the first priority of the NAH. However, the battery is what moves the car in reverse out of a driveway.

Hope that helps.

FWIW nothing like that has ever happened to me in 5700 miles and 5 months of ownership. But I haven't had to use the A/C yet either.

It gets late early out there. - Yogi

Our blue light comes on every morning for the first 5 minutes or so while the engine warms up the catalytic converter. The engine starts within seconds of moving the car. This is the normal operation of the car and has been that way for over 21,000 miles of driving.

Yep, I second that... When the car is cold, ICE comes on within 5 seconds of pressing the power button, even if not moving at all with the lever in park position.

Following Up: Went away for the 3 day weekend and got back home and the car was dead... the power locks didn't work, nothing. AAA came and jumped it (didn't know that was possible) and drove it in for service. Waiting on a diagnosis. I would be shocked if my issues were not related.

That actually sounds like good news. If the battery is dead (the 12V battery) and it was not holding a charge, the engine may have been overcompensating to try and rev up the alternator (or whatever charges the 12V battery). Do you know if this car was sitting on the lot for a while?

It gets late early out there. - Yogi