Folks,

I notice when I am decelerating and the IMA battery is charging from the deceleration, and I push in the cluth, the rpms go to zero, then bump back up, as if the IMA restarted the engine. Is this typical? Is this just a slow restart after the fuel has been cut to the ICE while decelerating?

Bill

 

I'm just curious but what gear, road speed, and engine RPM prior to pushing in the clutch are typical for when you experience this? I know I've seen posts about this in the past. I believe this was a huge part of the reason they chose not to offer a manual transmission for the US market anymore.

 

When I'm in 4th or 5th, usually around 3K rpms, but it can be higher or lower. If I were in the middle of s shift, I'm sure I would complete the shift before the rpms went to zero, btu it only happens if a hold the clutch in for a few seconds and wait; the ICE "stops", then restarts a momemt later. Not a real problem, mostly just a curiousity, although I swear I have seen the battery light come on for a split second before, as if it were a "real" stall. And it only happens if a have been decelerating long enough for the regen to kick in fully...

 

Sounds like what is happening is when it's in regen mode the fuel is cut (or maybe super-lean?) and the wheels are spinning the engine through the tranny, also spinning the electric motor of course, then as you push the clutch in power from the wheels cannot reach the engine, so it disengages regen and (assumes) you will re-engage the clutch soon enough for the shift so that it doesn't have to change the state of the engine, but as you leave the clutch in and the engine eventually stops spinning, then it decides it should keep it running with an IMA start and gas. I may be wrong, but that seems to me what might be going on.

 

I have seen this situation, also.

My theory is that duing the regeneration the ICE is just spinning along and when you engage the clutch, there is no fuel to sustain the RPMs. The computer corrects and then the RPMs go back to ~600.

I haven't seen a performance issue with this phenomenon.