Can hybrid engines start, even with the ignition off?

Dear Car Talk

Dear Car Talk | Apr 01, 2007

Dear Tom and Ray:

I took my 2006 Honda Civic hybrid to a store for an oil change. The manager told me he could not do oil changes on hybrid cars, because the engine can start even with the ignition turned off and the keys out of the car. He said he needed lineman gloves and would have to disconnect the electrical system in my Honda or he could get a serious shock. He said I must have noticed that the car would start all by itself even with the key out of the ignition. He said it does this to charge the battery. I never once noticed the car starting by itself. He said only Honda can safely change the oil in a hybrid. I have taken my Honda hybrid to other local service stations, and they all changed the oil for me without any problems. Is there any merit to what he told me? My previous car was a Toyota Prius, and I did notice a humming sound coming from the engine after I had turned it off. But even with the Prius, I had the oil changed at local service stations rather than go to the dealer. -- Robert

TOM: The guy was misinformed, Robert. Once it's turned off, this car won't start unless someone turns on the ignition.

RAY: It's true that an increasing number of cars, including some versions of the Prius, come with something called a "passive entry" system. With one of these systems, all you need to do is approach the vehicle with the key fob in your pocket, and the car "senses" that you have the key.

TOM: Once it senses that the correct key is close by, it will let you unlock the doors and start the engine (by push button) without actually taking the key fob out of your pocket.

RAY: But even with a passive entry system, you still have to push the "start" button, or the car absolutely will not run.

TOM: This guy may have had an experience with a hybrid where someone left the ignition on. Since hybrids are silent in their electric mode and only start the engine when they need to, it may have appeared to him to be off.

RAY: Then, if the hybrid's computer determined that the battery needed to be charged, it may have started up while he was working on it and scared the lug nuts off him. Who knows?

TOM: But if the car is legitimately turned off, it will not start by itself. And you can get your oil changed anywhere, Robert. Well, anywhere but from this guy.

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