I'm trying to figure out why my Prius refuses to glide sometimes. Has anyone else had this problem?

I was on my way into work this morning, the car is nice and warmed up (about 20 minutes in), and there's this long downhill section to a stoplight that I usually glide on. This morning the car absolutely REFUSED to glide down this hill. The battery was still blue (3-4 bars, maybe?). When I took my foot off the gas pedal, it would begin charging the battery with the electric motor. If I so much as tapped the pedal lightly (as if to glide), the engine would come on to provide thrust and charge the battery. I was well within the 30-42 mph glide zone (~35 mph).

Has anyone ever experienced this before? It was driving me batty this morning. I kept trying to get it to glide and it kept kicking the engine on! Eventually I gave up and coasted down the hill, letting the battery charge. Not such a bad thing I suppose, but I could've taken the hill a lot faster if the battery weren't charging!

 

There is a fine balance point between applying the gas and taking your foot off the gas to maintain a regen free glide. If you want to glide without charging you need to keep your foot on the gas very slightly and max out the mpg gauge, unfortunately this means that the the ICE will be on. Very similar to driving the HCH. Otherwise just pop the transmission into N for a nice coast without any recharge. Hopefully some of the prius drivers will add more info.

 

Thanks, I guess I should have specified that I was keeping my foot on the gas very slightly as required to initiate a glide. The car should have been gliding, but it wasn't. I wasn't maxing out the mph (going above 42mph), which would kick the engine on.

 

A little cruder, you could set your cruise-control and then'pat' the stalk to achieve the MPG you are after. If the charge and MPG is heaver than desired, 'one up' to add 1 mph. If the MPG looks too low, 'one down' to take away the 1 mpg. Not quite as delicate as the accellerator pedal, it works.

Bob Wilson

 

Yes I have had this happen before. I don't know why either. It does not happen often, but it does happen sometimes. I just chalk it up to the battery managment sytem.

 

That's illegal in my state (California). Those elsewhere should check their states' vehicle codes.

 

I've had this happen, as well. The car refuses to glide, when it should. You can either throw it into neutral or turn off the car, at a stop light.

 

Well, at least it's nice to know I'm not crazy and other people are experiencing this too... It happened to me on the way home from work today, too. Unfortunately this wasn't on much of a downhill and it killed my MPG average, but I made it up with a highway trip later on. Am I the only one that gets better MPG highway than city?

 

Absolutely. I dunnuh why they reverse it in the mpg rating. I'm about 10mpg more efficient on the highway. For one thing. there's more room on the highway for me to drive how I want without pissing others off. The other thing is those 1st few minutes of low mpg. If I make a series of 5min drives then each time the mpg is just warming up when I stop. When I do my 45min commute those 1st few minutes have almost no impact.

 

I have had it happen to me too. I think it happens when you have been gliding quite a bit and the engine isn't able to get the catalitic convertor temp to stay up. It isn't all bad though, if you let the ice run while still pulsing and gliding, you will see MPG in the 70's or 80's during the glide. after two or three min. , the ice will shut off and you will be back to the normal glide.