IMA intermittent assist issues

Red 01 · 08-13-2011, 09:50 AM

Hi I am brand new here, purchased a 2001 CVT Insight a month ago with 89K miles. I love the car but after the first week I clearly noticed a change in the assist mode was not always assisting. The SOC is always high. Sometimes the first 5 minutes of driving have no assist whatsoever but other days it assists with the first acceleration. I have seen it provide no assist under full acceleration after 15 minutes of normal driving (during which the assist was working fine) I have seen it start to assist, then drop to no assist during the same acceleration up to speed. There seems to be no discernable pattern, no warning lights, car was well taken care of.
I'm averaging 47mpg. The IMA battery is 2 years old, 3 control modules have been replaced. It is still under warranty and Honda says it is "normal" I did clean up the ground cable under the fuse box which seemed to help some initially. Does anyone have experience with this to assist me with my assist issues? How can I get Honda to be more aggressive troubleshooting, they dont want to do anything more than use their standard test procedures.
Thanks!

gilbertguy · 08-13-2011, 10:46 AM

What are the enviromental heat conditions when the assist is not working? There are thermal protection built into the software assoctiated with the battery temp. I've seen my assist affected after the car sat in the sun all day long on hot days. Could be something else but it helps the rest of us to know this piece of the puzzle.

Eli · 08-13-2011, 03:14 PM

If there are no error codes there is nothing wrong.

Red 01 · 08-13-2011, 11:08 PM

Quote:

Originally Posted by gilbertguy

What are the enviromental heat conditions when the assist is not working? There are thermal protection built into the software assoctiated with the battery temp. I've seen my assist affected after the car sat in the sun all day long on hot days. Could be something else but it helps the rest of us to know this piece of the puzzle.

Knowing there are thermal cutouts I have been looking at that as a possibility, our high temps here are in the mid 90's and one morning the car sitting in the sun might have been 100 degrees inside by 10am and there was no assist the first 5 minutes which made me suspicous of heat being the cause but it then started working normally and so many times the assist doesnt kick in at lower temps or works normally then stops that it is hard for me to believe that heat is the sole cause. I have driven one other 05 cvt Insight and it seemed to perform consistantly as I would expect my car should. My best guess is still freaky electrical issues due to a bad ground connection somewhere which I intend to persue further but hoped perhaps someone on the forum here would have more experience and advice for me. Is there some calibration for the 3 new battery control modules necessary that hasnt been done? I dont think my Honda dealer is really familiar with the car, he told me on a test drive that the IMA never assists right away on the days first drive but he wouldnt listen to my observations to the contrary.
It gets a little unerving at times pulling into heavy traffic not knowing whether I will get the assist or not.
Thanks!

Eli · 08-13-2011, 11:26 PM

Yeah, the Honda dealerships are woefully unfamiliar with our cars.

aisbell · 08-14-2011, 04:22 AM

Quote:

Originally Posted by Eli

If there are no error codes there is nothing wrong.

You sound like a Honda dealer

There can be problems developing that aren't serious enough to set an error code. In such cases, the problem will likely become serious enough to set an error code. But this can take many months during which performance is subpar.

The O.P. mentioned cleaning a ground under the fuse box in the engine compartment. There are actually two ground straps in that area, one from the engine and the other from the transaxle. So if you didn't clean both, look for the one you missed. Also, don't forget the 12 v. battery cables which can be corroded internally. And a weak 12 v. battery can cause confusing electrical problems, so check the condition of your 12 v. battery.

gilbertguy · 08-14-2011, 11:56 AM

I would disconnect the neg 12V battery terminal to make sure it is clean. Part of the reason I'm suggesting this for is to "reset" your IMA system. Once you hook the 12V back up and turn on the car you'll need to sit and idle the motor for a few minutes at 3-3500 RPM until the battery recallibrates. We've seen a few others on the forum that had issues that cleared up after a system reset.

One other question, you mentioned new modules, when were they replaced? Since you have only had the car for a month I'm guessing that you have never driven this car and seen it perform normally? Would have been good to see how assist was before the modules were replaced.

**Hybrid-Battery-Repair** · 08-14-2011, 12:40 PM

Quote:

Originally Posted by aisbell

The O.P. mentioned cleaning a ground under the fuse box in the engine compartment. There are actually two ground straps in that area, one from the engine and the other from the transaxle. So if you didn't clean both, look for the one you missed. Also, don't forget the 12 v. battery cables which can be corroded internally. And a weak 12 v. battery can cause confusing electrical problems, so check the condition of your 12 v. battery.

I'm guessing that cleaning that ground involved disconnecting the 12V which would have reset the IMA system and caused it to "seemed to help some initially".

Red 01 · 08-15-2011, 09:14 PM

Quote:

Originally Posted by gilbertguy

I would disconnect the neg 12V battery terminal to make sure it is clean. Part of the reason I'm suggesting this for is to "reset" your IMA system. Once you hook the 12V back up and turn on the car you'll need to sit and idle the motor for a few minutes at 3-3500 RPM until the battery recallibrates. We've seen a few others on the forum that had issues that cleared up after a system reset.

One other question, you mentioned new modules, when were they replaced? Since you have only had the car for a month I'm guessing that you have never driven this car and seen it perform normally? Would have been good to see how assist was before the modules were replaced.

I didnt clean the 12volt battery cable as the battery looked new and the cables connections were excellent with corrosion protection spray on them. I looked every which way I could to find the second ground cable without success, dont know where it is hiding. I only found one ground right below the fusebox on the drivers side fenderwell under the hood.
The car IMA performed consistantly for over a week after I purchased it in July and then without question in my mind was no longer assisting the same, I dont think it was something I just didnt notice.
Two control modules were replaced in in Jan of 08 and another in May of 2010. The IMA assist acts up usually once or twice a day driving 10 miles. Most frequently by simply supplying no assist at all well after the engine is warmed up and the assist has been working consistantly. Other times the assist will rise with acceleration and while still accelerating it will just stop rising and drop back to no assist. My IMA battery SOC is always high or full.
I have sent a detailed email to the Honda shop foreman here hoping he may get directly involved and resolve this.
I would love to get MIMA and just do the IMA control myself but dont have the $ or expertise to install it.
Thanks everybody.

gilbertguy · 08-15-2011, 09:40 PM

Does sound like there is something going on but nailing it down will be tough if you don't have a hard failure. I'm wondering if you've got a week relay or something that is affected by heat? Take a look at your relays for the IMA system and if you have two that are the same try swapping them with each other to see if you can get the problem to move. If it does that is a pretty good indication that you found the issue. Keep us informed. Sorry I don't have more, maybe someone on the forum with more experiance on this issue could help out.