Transmission problem or just Autostop?
#1
Transmission problem or just Autostop?
Hi All.
My HCH occasionally lurches forward if I'm slowing to a stop, decide not to stop, and step back on the gas. It's a hard thing to reproduce. I took it in for service and asked the dealership to look at this, but they said it was normal-- just the car coming out of autostop. If that's so, then I would think many people experience this... but I haven't seen it mentioned on these forums.
Are you folks having this issue at all?
thanks,
- Frank
My HCH occasionally lurches forward if I'm slowing to a stop, decide not to stop, and step back on the gas. It's a hard thing to reproduce. I took it in for service and asked the dealership to look at this, but they said it was normal-- just the car coming out of autostop. If that's so, then I would think many people experience this... but I haven't seen it mentioned on these forums.
Are you folks having this issue at all?
thanks,
- Frank
#2
Re: Transmission problem or just Autostop?
Without being in the car with you when it happens, it'll be hard for any of us to say something with any degree of certainty. I suspect your dealership is right... if you're coasting into a red light with your foot lightly on the brake, AS usually kicks in around 7mph. Letting go of the brake turns the ICE back on, and if you're already moving, it can be a little rough. However, there's been reports of people having trouble with the EGR valve, which can also cause some rough motion in the circumstances you describe. If your car is "brand new", it's probably the AS. If you've got about 10k miles or more, you may be one of the folks with a flaky EGR.
#4
Re: Transmission problem or just Autostop?
I experience this quite often, ito me it feels like the regenerative braking is on and and providing additional braking force, as you are are coming to a stop it ceases and just relies on the vehicle brakes, it can be unnerving, i also believe these cars dont have a brake booster and as with CVT transmissions they provide very little engine braking therefore they use the regenerative braking to aid braking force
#5
Re: Transmission problem or just Autostop?
Originally Posted by ftlum
Hi All.
My HCH occasionally lurches forward if I'm slowing to a stop, decide not to stop, and step back on the gas. It's a hard thing to reproduce.
My HCH occasionally lurches forward if I'm slowing to a stop, decide not to stop, and step back on the gas. It's a hard thing to reproduce.
Autostop engages at about 6mph as you're slowing down, in my experience (this assumes you were going faster than 8mph).
When the car lurches...are you going 10mph or less ? If so, it's the transmission - but it's not a 'problem', per se - it's the gear ratio being reset internally, along with the start clutch being disengaged, as the car's computers thought you were going to make a full stop. In a sense, you were, but got to see conditions ahead and change your mind. The car doesn't get to see this, however.
At speeds < 11mph, the CVT is 'automatically' in the lowest of it's gear ratios. In your case, it dropped back down to this ratio when you were slowing down. However, when you were at your original speed (probably significantly higher than 10mph), the CVT was in a higher gear ratio.
Being in the lower gear, you don't need to give the car as much throttle - if you just lighten up on the throttle (similar as when you start from a dead stop), you'll pretty much eliminate this lurch. It used to happen to me when I first got the car. As I became more acquainted with the CVT and throttle, I learned to ease up on the pedal if I was at a lower speed and didn't need to stop. Now, with 8mo. / 10K mi on the car, it's just second nature to me, and I don't really consciously notice that I'm manipulating the throttle differently when I'm in that speed range.
Try this, and see if it helps...
If the car has dropped below 6mph and engaged autostop, wait 0.5 sec after the engine restarts before applying throttle. This allows the start clutch to engage again.
If the car is still short of engaging autostop (> 6mph, but < 11mph), just go a bit easy on the throttle when reengaging it.
As you practice this in your own car, you'll gain a side benefit of learning to kick the car into the EV-mode fairly easily through your deft manipulation of the throttle.
For an example of a bad 'lurch' - try driving a new Civic Si if you get a chance (and can drive stick). Due to its gearing, that car could be started off in 2nd gear most of the time and still have good power. In first, you have to really baby the throttle if you want a smooth takeoff from rest.
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twolostminds
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11-17-2014 06:23 AM