P1637 MCM internal circuit failure
 

Hi all!

I have a 2004 HCH with 98,000 miles on it. Started getting the IMA light and CEL, but they were intermittent. Finally got them fully on. Removed the battery pack and did a fully discharge/recharge conditioning. That cleared some error codes, but the IMA/CEL still on. Decided to take to the Honda dealer, and they are telling me "P1637 MCM internal circuit failure. Software is up to date, need to substitute/replace MCM and recheck condition".
I have searched a ton on YouTube, and here (and the Civic Forums) and cannot find exact where the MCM is. The guy from Weber State University on YouTube has stupendously good videos ( ) but somehow, despite incredible detail on almost every other part of the hybrid system manages to miss talking about the MCM.

Where EXACTLY is the MCM?

If anyone knows of a video where it is replaced, could you point me to it, please?

If I buy one on eBay, I want to make sure I get the EXACT right part. Thoughts?

Many thanks!

Re: P1637 MCM internal circuit failure
 

Update: I found the YouTube video from the amazing guy at Weber Auto that describes where the MCM actually is!


When I look on eBay, places like Hybrid Battery World have an MCM for $25 (https://www.ebay.com/itm/314397483567) and the same thing for $60 (https://www.ebay.com/itm/314624846378). What do I need to know here for why one is $25 and the other $60

There's also one listed for $85 (https://www.ebay.com/itm/233023538679) which came is "Removed from 2004 Honda Civic hybrid. Fits the following models. 04-05 civic hybrid mx w. Manual transmission, California emissions. Dealer programming required"

As already stated, I have a 2004 HCH with manual transmission, so I am leading towards this $85 one, but is there really a difference between these MCMs for the automatic vs. manual? I can sort of see why there might be.

Thank you!