A very strange thing happened to my 2007 HCH II CVT recently. Suddenly the fuel efficiency decreased from about 43-44 to 36-37 mpg. There were three events that I could see possibly related to this….a new set of tires, CVT oil change, and complete discharge of both the IMA and auxiliary lead-acid batteries (I left a map light on for about a week) Then something else happened….my electric power steering assist failed (quite unnerving…the steering became very heavy and hard to control). I managed to park the car, then I turned the ignition off and back on per the instruction manual, which reset the steering. I was then able to complete my journey without any further problem.
I took the car to my Honda dealer and reported the steering problem and also asked them to check whether the right grade of oil had been used for the CVT. The technician reported that there had been a short in the power steering system (quite worrying that this could actually happen), but that the CVT had been refilled with the right grade of fluid. On the written report, only “reset code” was noted.
To my delight, I now found that the fuel efficiency was back up to 43-44 mpg! Could it be that discharging the battery had changed a code such that the odometer was under-reading? It has to inaccuracy on the miles driven since I check my mpg against the gallons used between fill-ups.
Has anyone else experienced anything like this? Or an electric power steering failure?

 

Hi there! I went through some of these issues recently. Got new tires, along with the rear upper control arm replacement, as well as CVT fluid and oil change at 60,000 mi.
I also noticed a steep drop of FE from ~55 to ~47mpg. This is both by the computer and by manual calculation at fill-up. I also went back to Honda and they reassured me that the fluids added were correct. So I guess I blame the new tires (Yokohama Avid H4S), although that still seems too severe for tires. ANd the way the car is driving, it feels more sluggish overall, esp during acceleration. Tires feel a little sticky during glides, but not awful. Another friend suggested the CVT fluid could be at issue, but I don't know what I can do there...

No battery issues, though, or power steering problems. I wouldn't be too worried about your power steering right now unless it happens again. And if your MPG is back up, then feel lucky, my friend