I took my 2006 HCH into the dealer today. After the software "upgrade" they did on the car two years ago, I've lost 10 mpg on my vehicle, the battery continually drains from full to two bars in a matter of blocks and sputters from a stopped position. I have 78k miles on my car and wanted to see about getting the battery replaced before the 80k on the warranty hits. I was told today by my local Honda dealer that the IMA is perfectly fine and that the issue lies with my engine. They're telling me my engine is not functioning properly and it's really my IMA that is driving the car and that's why it's draining so quickly. They said it would cost me $150 to continue diagnosing, so at that point I told them to stop. All my car symptoms are identical that I keep reading on the 2006 HCH. Anybody been told that their IMA is fine, but that the actual engine was a problem??

 

After getting a whole lot of run around from Honda (oh, it's your engine, oh it's your fuel, oh it's your fuel injector), they then crashed my car's computer. They brought the computer back up, but then couldn't get any accurate readings off of the diagnostics. They asked me to drive it for a week. I took it on a weekend get away and for the first time in 2 years (since the software update), I got 39.7 mpg. However that was short lived. By the end of the week, my battery was discharging within a few blocks of my house again and took it back in to Honda to complete their assessment. Turns out my IMA is bad. Funny because that's what I told them was the problem at the very beginning of this nightmare. At least it's still under warranty and it's now getting replaced next week.

 

Your kinda right about the IMA battery being bad. When the car goes from full charge to two blocks, its called a recal (short for re-calibration), it is caused from one or several sticks in your IMA battery pack being weaker than the others. Your IMA battery is made of 22 battery sticks, and each stick literally is made up of 6 little Nickle Metal Hydride D-cell batteries. 1.2 volts per cell, 7.2 volts per stick and 158 volts for the whole battery. The computer performs a recal when it can't determine the state of charge of the battery because the pack is out of balance (meaning the 'bad or weak' sticks are at a discharged state while other good sticks are at full charge). The IMA battery can be taken out, disassembled, the sticks cycle charged and refurbished, and the battery re-installed and all will be fine for several years ( which is exactly what the dealer batteries have had done to them) but you need to be mechanically inclined.

The transmission shudders from 0-15 MPH acceleration because of the starter clutch being worn in the transmission. You can fix this by following the steps here: http://api.viglink.com/api/click?for...13717776035177

Myself, and several others around this forum have rebuilt our IMA batteries and as for myself I have also fixed my transmission shudder under 15 MPH problem, fixed my wheels cupping on the rear due to control arms, fixed my catalytic and O2's triggering a P0420 code, and spark plug change. I bought the 06 HCH w/ 165000 miles for $5000 and put $1000 into repairs and now am getting between 42-51 MPG. You can literally make this car last forever if done right. However, you have to be mechanically inclined.

 

Thanks for this post and the reply. I am just starting to see this behavior in my '06 HCH as well (~84k mi), and it is very frustrating. Most days I will pull out of the driveway in the morning to find no assist and 2 bars on the gauge. On the freeway, I will occasionally experience several recals within a 20 minute period even though I drive quite conservatively (coasting downhill, rarely going much over 2k rpm). I'm doing more city driving recently, but given my driving habits, struggling to get 35 mph still seems incredibly poor.

I already had the IMA battery replaced once somewhere around 40k miles. Looks like it is time to pay Honda service another visit.