Honda Insight Forum banner

1 - 20 of 57 Posts

·
Registered
Joined
·
42 Posts
Discussion Starter #1
Hi folks.

Two years ago (2018), I was so certain that a 100A fuse was the mysterious fix I'd been searching for since my first post about IMA issues in 2013.
Within a week my IMA light was back on and 12V was draining again. I was too disheartened to post an update, and the car has since sat sheltered, but idle.

Every now and then, I re-read the dozens of forum posts I've read so many times before, suggesting bad ground straps, grid chargers, bypassing the IMA... hoping I'd find something new, something to give me hope. I've repeated countless diagnostics with a multimeter and manual in hand, but I'm not an electrician or a mechanic, so there's only so much I can do myself. I've thrown good money after bad money, feeling especially "in for a pound" once I agreed to give the dealer CAD 3000$ to put in a "refurbished" IMA battery 3 years ago, since I was unable to get the car to the US to work with one of you fine folks.

I've hired mechanics and electricians with a genuine interest in the car, but no one's been able to crack the code (P1575). For all I know, my new IMA was sourced from scrap and had problems of its own. The IMA battery itself appears perfectly balanced and reading 15V across each pack, (details in the first link). I've bought it a new 12V twice in the past 2 years. Replaced all ground straps. The electrician who thought he'd found the issue in the 100A is out of ideas. For all I've spent, I probably could have bought another Insight.

It's been a real source of unhappiness in my life and I think I have to get rid of it. I posted an ad on Canada's equivalent of Craiglist (Kijiji), but am not hopeful to find anything other than scrappers willing to "take it off my hands" for a pennance.

As I was prepping for a visit from a potential buyer (that never came), I brushed it off and boosted it using my other car's 12V. I saw those few green bars as it tried to charge the IMA for 2 seconds than give up, pretty standard after a battery pull. I used my OBDII reader to reset the CEL and watched it rethrow the P1575 a couple times. The engine ran as smooth as ever for 10 minutes, but of course died instantly when I removed the jumper cables (because the 12V isn't getting charged). Same with the IMA switch off (but BCM still attached). I'm sure it's just been so long the hopelessness has worn off a bit, but now I can't sleep. Feeling like an addict, I came here delving again, and stumbled on a bypass method I hadn't tried before that involves cutting some wires:
87529

There's a time where the thought of cutting any wire would make my stomach turn, especially since this suggests writing off my "new" IMA battery, but perhaps if I'm in a place where I'm about to write off the entire car, I might try this (despite my complete lack of foundational expertise). I'm hoping someone here can talk might talk me into or out of it as they see fit.


I'll close out with my favourite picture of my car, taken in 2005 when I was very much in love with it. This has got to be the closest thing to an abusive relationship with something that isn't sentient.
87528
 

·
Administrator
Joined
·
12,147 Posts
P1575 MDM Voltage Problem.

Assuming the 100A fuse isn't blown etc then ....

1) With a 200V meter measure the voltage at the top two IMA terminals as someone turns on the ignition?

It should rise very rapidly as the pre charge contactor engages but then in your case probably falls back again as it disengages due to the fault code? Does it do this?

2) Find the VPIN orange wire between the MDM and MCM connector B pin 16.
Tap into this wire and measure with a 5V meter between the VPIN and ground MCM connector B pin 25 red/yellow.
It should jump up to about 2/3V when you turn on the ignition, but in your case it may jump up and then go down again quickly or it may not change at all.

What does it do?
 

·
Registered
Joined
·
836 Posts
Hi Alain,

I also could not bear to cut this wire. Using the wiring diagrams posted here, I found where it entered the ECU at the front of the car (much easier to get to, by the way), and figured out how to remove the wire and pin from the connector without damaging it, and sealed it in tape and secured it so it would not short on anything.

I would not blame you for wanting to sell, but if you post it for sale here, and bump it as frequently as you can (which sadly is not frequently enough - once a week should be permitted) someone in your area who browses the forum a few months from now will be very happy with their discovery.

If you do decide to troubleshoot this, send me a PM.
 
  • Like
Reactions: alainbryden

·
Registered
2006 Honda Insight MT
Joined
·
609 Posts
Bypassing the battery is also an option. If you want to test it out, you can flip off the hybrid battery breaker and unplug the BCM connector. 12V will charge below 4000K RPM and you'll get the CEL/IMA lights but the car will drive fine. It's a good way to test if you want to bypass the battery without doing anything irreversible first.
 
  • Like
Reactions: alainbryden

·
Registered
Joined
·
437 Posts
"This has got to be the closest thing to an abusive relationship with something that isn't sentient."

Okay...
Did you ever owned a late 1990 - early 2000 Volkswagen?
 

·
Registered
Joined
·
42 Posts
Discussion Starter #6
@retepsnikrep Thanks for the interest. I appologize if it takes me some time to get the answers - my limited experience makes simple diagnostics like this a day project. Nothing is intuitive, I have to pore through the manuals, look up the jargon, triple check everything, and make sure my affairs are in order first.

I believe the 100A fuse is not blown because is showed low resistance with a multimeter, but I've also read that these bigger fuses can appear fine, but be failing under high voltage (i.e. while the circuit is live). Not quite sure how to test that (e.g. measure the voltage and current across the fuse while the car is starting/running?) I'm a bit scared to reach into that tight spot with my multimeter leads.

@mpg_numbers_guy I had been thinking about bypassing by disconnecting the BCM, but read comments like this suggesting that it would still run down the IMA battery to charge the 12V until both were bone dry.

@*sean* I'm still flip-flopping on what I want to do, but appreciate the outreach. Seems like such a waste to give up on the fresh IMA battery. I stumbled on some papers for it today. It had a warrantee valid from 2017/01 to 2020/01. Wish I'd found that years ago and reached out to the seller (Dorman) for ideas on why it wasn't working. As long as folks have other diagnostic ideas, maybe I'll give them a try.
 

·
Super Moderator
Joined
·
8,418 Posts
Ugh -Dorman battery with 3 year warranty. Sometimes that is about all they do - warranty plus a few months:(
 

·
Super Moderator
Joined
·
8,418 Posts
I'll close out with my favourite picture of my car, taken in 2005 when I was very much in love with it. This has got to be the closest thing to an abusive relationship with something that isn't sentient.
Ah "sentient." Yes they do that and some folks never get over the old love. At least you know all the old gal's foibles so maybe just relax a little, ignore the wrinkles, and hang on for the long term :)
 
  • Like
Reactions: Arbus

·
Registered
Joined
·
42 Posts
Discussion Starter #10
@retepsnikrep I'll do my best.

I'm not familiar with pinouts and locations yet, but I'll dig and try to find the correct ones. I found a similar thread where you helped someone with a P1576, but instructions are a bit different. I'm trying not to require too much hand-holding, but if these are wrong and you have any pictures, it would be incredibly helpful. By any chance, did I interpret your instructions correctly:

1. By "the top two IMA terminals" do you mean these?
1600178752053.png

2. By "VPIN orange wire between the MDM and MCM connector B pin 16 and ground MCM connector B pin 25 red/yellow" is this it?
87561

Does that correspond to this location? (picture is my own)
87562



I currently have my 12V disconnected and trickle charging, but I'll get these results back to you as soon as that's done (assuming I found the right places to test).

Thanks again.
 

·
Registered
Joined
·
545 Posts
I wish you were near someone with a parts car (like me) and we could just swap out components that we don't understand. I always wanted to understand how this all works, but it turns out to require a lot of brain power. Ouch. I can't seem to do it. I hope you persevere. I understand how you feel.
 

·
Registered
Joined
·
42 Posts
Discussion Starter #15
@retepsnikrep Got the answers. Both align with what you predicted:

1) Voltage reads 146V while the car is in accessory mode, holds as the car starts, then the IMA light comes on a few seconds later (accompanied by a click) and it dropped to 109V quickly. It then rolled steadily down to ~95V (over about 5 seconds) where it sat for about 10 seconds. Then we shut the car off.

2) Was a huge pain to get a steady read on those wires, but I got there:
Started out at 2.8 volts, then the IMA light came on and it dropped to ~2.0 Volts almost immediately, then tricked down to 0 within a few more seconds.

Thanks again, looking forward to your thoughts.
 

·
Administrator
Joined
·
12,147 Posts
What is the voltage of your IMA battery measured at the grid charge connection points?

I think you need to try swapping out parts now as Kenny suggested.

1) Swap the MCM now with a known good unit? (They are cheap enough second hand)

2) If that doesn't work you will have to try swapping out the MDM for a known good one. (Ditto)

I suspect the problem might be with the VCU voltage converter unit built into the MDM.
 

·
Registered
Joined
·
42 Posts
Discussion Starter #17 (Edited)
IMA battery is at 150 V last I had someone check, I don't have a grid charger or know how one would be hooked up, so I'm not sure what the official "grid charger connection points" would be.

Unfortunately, I'm in an insight "cold spot" up here in Halifax, Canada, so there's now way I'd get access to an MCM/MDM without outright buying them.
 

·
Registered
Joined
·
42 Posts
Discussion Starter #19 (Edited)
According to my searches, the MCM part number I need is "1K000-PHM-A01".
  • hondapartsnow.com sets the bar at the "discounted price" of USD$ 647.42 (CAD$ 933.45) - plus shipping and duty and tax is CAD$ 1242.43. For a salvaged MDM. Price to beat.
  • Ebay only has one right now at USD$ 199 coming from Nevada. That's estimated at CAD$ 355 taxes and duties in.
  • Part number doesn't appear to be listed on RockAuto
  • Nothing on kijiji - not surprising since the car was never sold in Canada.
Any thoughts on other places I should search? It's looking really expensive for just a test to see what happens.

Having trouble finding a part number for the MDM (not even sure what it is, always seems to be "bundled" with the DC-DC converter in pictures) so no results for that yet.
 

·
Premium Member
Chicago & Detroit
Joined
·
991 Posts
Call Halo Auto parts in Toledo, OH.
Keep trying if no response. They're there. Brent has the parts. 614-949-0529 or (419)4604367
 
1 - 20 of 57 Posts
Top