[BabsV]

I had an appointment at the local Honda dealer to have my brakes replaced and tires rotated and by the way my IMA light just came on 2 days ago. AFTER doing the brakes and alignment, they told me that despite replacing the IMA battery 5 years ago, my Motor Control Module (MCM) is bad and constant deep cycling has caused that IMA battery to fail. This also means that the 12V battery is not always getting charged and the car will leave me stranded if it isn't fixed. I've had this car for 20+ years, so was ready to lay down another $3000 for another IMA battery but the saddest news is that Honda has discontinued the MCM; there is no fix. Should I find someone to buy my car for parts, or search for a 2000 MCM and a mechanic to install it? Where should I start to do either?

 

[Honda hybrid442]

The mcm is super easy to install and I have a spare one for sale. Pm me and I’ll talk ya though the install.

 

[Honda hybrid442]

Please post your location ,you may be close by and I could help install.

 

[BabsV]

Please post your location ,you may be close by and I could help install.

Thanks but no luck... I'm in Grants Pass, Oregon. I'll PM you about the mcm, hoping that by super easy you mean like adding RAM to a laptop.

 

[Honda hybrid442]

Pretty close, flip the ima switch in the back, remove some 10 mm bolts and carpet take off the cover and unplug the mcm, replug the new one .

 

[retepsnikrep]

First of all you should get the IMA codes the dealer pulled so we can give our view. (You have paid for them)

Ask them for the full diagnostic code printout that has lead them to their conclusions and post it here for advice.

I would be very surprised if the MCM is bad as they claim.

 

[jime]

^ Spot on IMO. Honda dealers seem to have a habit of telling customers they need a new MCM or BCM, or both. It is rarely the case. Your problem is probably the battery itself. Is it a Honda replacement?

Since it just started coming on, you may be able to extend its life by a year or more by installing a grid charger. Many have had such experiences.

There is a reset process for the light, BUT it doesn't solve the basic problem so don't get into the habit of doing it. Try removing the 12V negative terminal clamp for a half minute. That would go a long way toward confirming that your MCM is good, and it is a quick test.

You will lose any charge bars when you do this reset, so run the engine at 3500 RPM for a few minutes - after it warms up a bit. That will give you charge bars. As you drive you will get all the bars back.

AGAIN, this doesn't solve you problem and should not be a regular habit since it just hammers the battery even more. Once is ok.

AND AGAIN, as retepsnikrep emphasized we need the trouble codes to be able to offer much help.

 

[Willie Williford]

An easiest/quicker solution for resetting everything rather than removing the battery connection is to remove the fuse #16 in the fuse box in the engine compartment for about 15 seconds and then reinstall. Then follow the old mans suggestion in post number 7.
You are apparently a new member, welcome to the family!

 

[jime]

Then follow the old mans suggestion in post number 7.

Who calling who old. I may be a few days older but I'm not nearly as crusty

All those fuses - I can never remember which one

Yes, welcome new member!

 

[BabsV]

First of all you should get the IMA codes the dealer pulled so we can give our view. (You have paid for them)

Ask them for the full diagnostic code printout that has lead them to their conclusions and post it here for advice.

I would be very surprised if the MCM is bad as they claim.

Thanks! I saw that advice in another post but of course they informed me of my problem at the end if the Friday workday. I'll get those codes on Monday.

 

[BabsV]

^ Spot on IMO. Honda dealers seem to have a habit of telling customers they need a new MCM or BCM, or both. It is rarely the case. Your problem is probably the battery itself. Is it a Honda replacement?

Since it just started coming on, you may be able to extend its life by a year or more by installing a grid charger. Many have had such experiences.

There is a reset process for the light, BUT it doesn't solve the basic problem so don't get into the habit of doing it. Try removing the 12V negative terminal clamp for a half minute. That would go a long way toward confirming that your MCM is good, and it is a quick test.

You will lose any charge bars when you do this reset, so run the engine at 3500 RPM for a few minutes - after it warms up a bit. That will give you charge bars. As you drive you will get all the bars back.

AGAIN, this doesn't solve you problem and should not be a regular habit since it just hammers the battery even more. Once is ok.

AND AGAIN, as retepsnikrep emphasized we need the trouble codes to be able to offer much help.

Thanks to all commenters! Whatever the outcome, at least I have options.

The replacement IMA battery 5 years ago was a Honda. When the light came on this time, I looked for alternatives and decided that I would go with Bumblebee.

I did the reset (both ways, just for fun 😂). On starting, the CEL returns immediately, there is a quick 3 bars charging indication, & the IMA light returns in ~2sec. No bars returned when ran at 3500 for 2-3min. I didn't drive it yet but will need to later today.

I didn't know to ask for the code printout before but there are 2 codes on my invoice, paraphrased here: found code 58 IMA battery discharge problem, tested and confirmed, recommend replacement. During test drive code p1565 MCM charge problem illuminated the charge light...confirmed... No factory repair available.

 

[jime]

The P1565 is "Motor Commutation Signal Problem.) The "58" they list is a mystery to me at the moment. I don't find that code in my lists. Anyone?

It could be a wiring problem caused by moisture or by rodent damage. Both have been reported. It could also be more serious problems such actual commutation sensor failure.

You can read other members experiences with the P1565 by simply typing P1565 into the search line at top of page. You will find lots of reading. Experiences vary as you will see, so it requires diagnosis time by a genuinely qualified Insight tech. Honda doesn't have many left since the car is well over ten years old

 

[Honda hybrid442]

We are the honda techs .

 

[jime]

The replacement IMA battery 5 years ago was a Honda. When the light came on this time, I looked for alternatives and decided that I would go with Bumblebee.

I'm a little confused. Do you have a new BumbleBee or are you contemplating buying one?

 

[BabsV]

I'm a little confused. Do you have a new BumbleBee or are you contemplating buying one?

Just contemplating since the light came on. The current IMA battery is a Honda replacement from 2015.

 

[retepsnikrep]

IMA DTC code 58 is listed as charge/discharge balance problem.

P1565 is a commutation sensor problem.

It needs proper hands on step by step by step diagnostics with test gear/meter etc.

Has your car got a problem with dampness inside?


What I would do.

1) You say the IMA light comes back on pretty much straight away.
We need to know which code/s have come back.
So read up on the blink code method of reading codes and confirm which codes you now have.
You might only have one, or both, or something else.

2) I would measure the ten BCM voltage taps for my own peace of mind and note the readings to get a battery condition baseline.

3) I would check carefully for loose plugs and nibbled wires in the IPU compartment.
I would unplug and replug all the MCM and BCM connectors.
Especially MCM connector D the commutation sensors.

4) I would look under the bonnet at the commutation sensor connector and check for wiring damage etc.

Report your voltages/findings etc then we can advise further.

 

[jime]

^ While I agree entirely with your suggestions, I haven't seen any indication that she would be able to do all of this.

It needs proper hands on step by step by step diagnostics with test gear/meter etc.

I do not see any indication that she is that set of hands. It's too bad she is so far away from Scott. I just checked the distance and it is 720 miles approximately. Maybe someone will know a decent and motivated mechanic somewhere closer

 

[eq1]

IMA DTC code 58 is listed as charge/discharge balance problem...

Just to be clear, the 'charge/discharge balance' here seems to relate to 12V battery, not the IMA battery. For example, the first troubleshooting step says, "Check the 12V battery," and asks, "Is the 12V battery OK?" If not, "charge or replace the 12V battery," if it is, 'turn the ignition switch ON, start engine, and if you don't see the 12V battery warning light everything's OK'... There's only one other step: If the light comes ON, check the idle speed, and if the idle speed is OK, then the manual says 'it's just an intermittent failure'.

Weird code.

...So read up on the blink code method of reading codes and confirm which codes you now have.... 2) I would measure the ten BCM voltage taps for my own peace of mind and note the readings to get a battery condition baseline.

Here's a link to 'how to read the blink codes': Misc. RESETS

And one on how to measure voltage taps: The quintessential Insight NiMH voltage thread

 

[eq1]

...No bars returned when ran at 3500 for 2-3min. I didn't drive it yet but will need to later today.

I like Peter's plan...

In the interim, like before your next drive, might be good to turn the IMA battery pack switch OFF, check your 12V battery and 12V system grounds, one from battery negative post to firewall, 2 to lower right hand side of air intake box, make sure they're actually connected, clean/corrosion free, etc.

If/when you do open up the whole IMA compartment, might be good to pull the connectors from the left hand computer on top of the pack - if you need to use the car before getting everything squared away. Turning the pack OFF and pulling those connectors is effectively bypassing the IMA battery pack and you'd be driving 'gas-only', the car will start on the 12V battery/starter (which is why you need to make sure that stuff is in good shape). In this config, you'll see the 12V battery warning light occasionally (over 4000 RPM), it will go away after some minutes.

It's possible(?) the commutation sensor signal error might prevent proper 'gas-only' operation. I'm not sure about that...

 

[BabsV]

Just to be clear, the 'charge/discharge balance' here seems to relate to 12V battery, not the IMA battery. For example, the first troubleshooting step says, "Check the 12V battery," and asks, "Is the 12V battery OK?" If not, "charge or replace the 12V battery," if it is, 'turn the ignition switch ON, start engine, and if you don't see the 12V battery warning light everything's OK'... There's only one other step: If the light comes ON, check the idle speed, and if the idle speed is OK, then the manual says 'it's just an intermittent failure'.

Weird code.



Here's a link to 'how to read the blink codes': Misc. RESETS

And one on how to measure voltage taps: The quintessential Insight NiMH voltage thread

Thanks for the links. I will check them out. This morning I found the Mike D documents on blink codes and got 12 mdm voltage problem and 66 battery module individual voltage problem.

I had already checked my 12V charge and its ground wire looks okay but After reading through the forum last night, i saw comments about grounding straps. Sure enough the 2 easy-to-see ones are so fragile that they pull right out of the crimps. My next step is to go buy some real tools so that I can remove these probably frozen bolts. (I used to have real tools BTW but my house was robbed about a year ago and I never replaced them)