RPM / Tach Problem !!!
 

I noticed this yesterday and this morning:

Car: HCH2 with 7100 miles, no maintenence performed yet, 30% oil life left.

Problem: At highway speeds, when the tach gets up around 2500-3000 during acceleration, it seems to get stuck there for a while. When I let off the pedal, and even when I touch the brakes, the RPMs stay at 3000!?!?!
This happened when the car was warm - I didn't notice it when the engine was cool (but that's not to say it didn't happen then)

After staying there for a while it will eventually "release" and go to the normal RPM. I do notice that the FE display and the Assist/Charge display both seem to be responding to my foot properly.

At this speed, however, I can't tell (ie - hear) if the engine is really at 3000 or if the needle is simply getting stuck. I need to experiment from a full stop with the windows rolled down on a quiet road, but I'd rather let Honda figure it out.

Possibilities:
1) CVT isn't transitioning properly - it could be getting stuck at one ratio (this is what I'm afraid of - but it's what I think it is).

2) Needle is getting stuck

3) Computer/wiring do deliver RPM value to the needle is faulty.

If anyone has any ideas, please speak up.

Thanks

Re: RPM / Tach Problem !!!
 

- CVT Speed Sensor faulty, improperly mounted or faulty wiring.



Cheers;


MSantos

Re: RPM / Tach Problem !!!
 

ah... are you sure it's not working correctly. It's a CVT, so the ratios are going to be changing while the rpm can remain constant.

If you were to floor the gas pedal, you will see the RPMs remain at (near) red line while the car speed goes up (the CVT is selecting bigger and bigger ratios).

Re: RPM / Tach Problem !!!
 

I'm quite sure it's not working right. On the way to the dealer, I gunned it a little during acceleration. My speed went up to 60 MPH, and the tach went up to 4500 RPMs (I went that high so I could hear it).

I immediately let my foot off the gas and coasted down to 40 MPH, but the tach REMAINED at 4500 for about 10 minutes (until I braked enough to come to a complete stop). I could still here the engine revving at that high level.

I've put over 7000 miles on this car, and I know all of its quirks. Trust me, this isn't normal. The CVT appears to want to stay CONSTANT rather than CONTINUOUSLY VARIABLE.

Re: RPM / Tach Problem !!!
 

I agree... that's a problem.

Re: RPM / Tach Problem !!!
 

My initial thought was that the throttle was stuck. This car has a "drive by wire" system, so there's no throttle cable, but the throttle sensor on the pedal could be defective or a carpet mat could be holding the pedal down. All of those thoughts went out the window when you said you could go slower (even almost stopped) with the engine still revving at that speed. It's got to be a CVT problem.

Quick question... if you tap the throttle, does it bring the RPM's down?

Re: RPM / Tach Problem !!!
 

If I tap the throttle, it doesn't come down. It wants to go higher then stay put at that higher RPM. I took it to the dealer who said they couldn't duplicate and tried to educate me on the CVT. But I was having none of it. So I went to the dealer to take the tech on a test drive and sure enough... it was fine. !!?!?!?!?

Something was definately wrong, but it's gone now. While it was there, I had them do the A1 maintenence since I was down to 30%. Maybe that did something - but I doubt it.

Re: RPM / Tach Problem !!!
 

Sorry for bumping such an old thread, but I haven't been able to find mention of this anywhere else on the Internet, and only one other thread on this site. (https://www.greenhybrid.com/discuss/...pm-range-8958/)

I am having this issue with my 2006 HCH II as well, so I've documented this with a camera in order to help my dealer fix the issue, and perhaps help others that are having the same problem. Does anyone know the outcome of this particular issue for the thread starter?

I posted a video with annotations that details the issue to YouTube:
http://www.youtube.com/watch?v=UXKy3_xba5o

Re: RPM / Tach Problem !!!
 

To Heaviestcat:

I can only assume that when I had this problem, it was atributed to a USED TIRE that I had to buy only a day or two prior. I had ruined a tire by running over a metal "chunk", and I bought a "same size" used tire to get me by while I waited on the new Dunlop to arrive. My car had only about 7000 miles so my tires were still virtually new.

I had the used tire on for several days, and the phenomenon only occured within that window. Once the new Dunlop was put on, I never saw the phenomenon again.

Although there's no proof, I can only assume that perhaps the tire was bad, or the used tire had less tread, and thus a smaller diameter such that it was screwing up the CVT computer. (Not sure how all of it is tied together, but it makes sense).

I would suggest having your tires checked for even wear, balance, etc. Rotate them and see if the problem goes away. If so, get a new set.

Good Luck,
FamilyMan

PS - My car now has 65k and this problem has not returned.

Re: RPM / Tach Problem !!!
 

Sure this is really a fault? I have this behavior too, only it occurs at higher speeds. Need to get above 125 km/h before the rpm gets stuck. I thought this was intentional, sort of like locking the gear at high speeds.

I have had one or two tires replaced too. Should I do something about it? I very rarely drive at 125 km/h or higher, but still, I like the car to be 100% OK.

Can anyone else confirm that their HCH2 does not behave like this, no matter the speed? (Ehrm, I'm not asking anyone to drive at illlegal or dangerous speeds. ;)) Only the front tires are involved in the speed sensing, so I only need to make sure they are as similar as possible, right?