Skypig said:
On a good day I can nearly coast from Tejon Pass (4195 ft) to the base of the Grapevine (700 ft), about 13 miles. After passing the summit, I slowly accelerate to 85, roll the throttle off and let the IMA charge until it hits 65, then repeat the process. This completely charges the IMA battery by the time I get to Tejon Ranch (6 miles) where the steepest grade starts. At that point, it stays at 65 to 70, throttle off, for another 7 miles.
<snip>
Ok I've got my second cup of coffee down.
So its during this leg of your commute that the codes are readily seen?
Again not necessarily always but more often than not?
These conditions may be one of those unusual driving situations that the engineers didn't foresee. Yes you didn't begin to see this problem until recently but we've gotta start somewhere. Stepping back and trying to look at the bigger picture sometimes helps.
Fuel cut-off mode for such a looong duration at high manifold vacuum may be the culprit. Observe the fuel trim values for a "normal" leg of your commute. Both short term and long term are nominally +-6%. On Honda a +-19% will set a fuel trim code, but if you approach this value and then "rapidly" try to use ICE power the engine may balk in that these values are used to tweak the injector on time. You may be getting a momentary lean hiccup.
HTH!
TO: Willie Williford
True of newer "technicians". However, in this case any wire that was going open circuit would set a code. And by golly that's what's happening, misfire codes. So you can be assured that such a wire must be related to this system. And as you are aware it can be virtually any related engine control that is not part of a sub-system which would set a more specific code.
Lets put our heads together here.
All I can think of right now is that either the CKP (crank shaft position) or TDC (top dead center) sensors may be noisy. A full blown open or short would cause a subsequent code. But a damaged wire or connection could cause just enough of a signal loss to be the culprit.
The ECU is on the right side floorboard and the only connectors are at the sensors themselves or the ECU. The ECU is under the carpet and a shield so its unlikely (read virtually impossible) for it to have been damaged when the cabin air filter was replaced. But maybe worth a look. If your gonna go this route Skypig you'll need the Honda ETM. The narrative description(s) needed to substitute for a pic is beyond me.
I'd give it some time to more clearly present itself rather than chasing the long list of our collective theoretical leads.
HTH!
