Just purchased ("as is, no warranty") an '07 Honda Accord Hybrid from a used car lot, 45,000 mi.
After I stopped for gas on the way home, I opened the gas cap rather suddenly, but replaced it (went to another station where I had left my credit card).
Then, the IMA warning light came on along with the "service engine soon symbol".
I got a new gas cap (as sometimes it will cause the engine symbol to come on), but the IMA warning yellow light, after disappearing on a restart, now came back on (with the engine symbol), after it warmed up. Now I'm worried that the IMA is not working, on this "new" used car purchase.

 

I just found out from the Honda dealer that it was a bad IMA battery.
That is good news for me, since it is covered under Honda Warranty for
80,000 mi. or 8 years....and I will get a new IMA battery for free under warranty on an '07 Honda Accord Hybrid that I just bought (45,000mi) for under half the original retail price.

 

HAH does not have CVT.

 

Dear Rolex,
There was no change in assist apparent when the IMA light came on....it seemed as if I
was actually getting 36mpg at the time of the IMA indicator light. The dealer said they would need to take the car for a day and thoroughly test it to see for sure if it was actually the IMA battery. The next day, they said it was, and replaced it ($2990 value)
for free under warranty....but since you said it might not have been bad, just wasn't reset right....that could be ....I'm still glad I got a brand new IMA battery, in this, my dream car that I just bought used ($45,000mi and paid $15,700 plus taxes=$16,800)
I thought it was a pretty good deal.