HCH1 Hybrid ECU/MCM compatibility

[Mario]

Duty cycle is the ratio of time the signal is high or low - for example, 30% duty cycle will have the signal high 30% of the time and low 70% of the time.

Frequency is how often those pulses occur, or how short or long they are. Low-frequency pulses could be, say, 3 seconds high and 7 seconds low. That's obviously hardly even PWM, but you see what I mean. Higher frequency could be something like 3µs on and 7µs off.

These are just examples obviously, but that's the difference. And retepsnikrep's thread looks to be a good source of information.

[JohnVirginia]

Thanks. Going with Mike's solution would probably be best for me.

vtbeerloverguy: is the vt virginia tech?

[vtbeerloverguy]

Yep, I'm a Hokie.

Does Virginia refer to:

a) University of
b) Commonwealth of
c) The name of your baby's mama?

[Subdewd2]

Thanks Mario, good description, makes sense now. I actually need this info, want to bulid a MIMA_L

[JohnVirginia]

Originally Posted by vtbeerloverguy

Yep, I'm a Hokie.

Does Virginia refer to:

a) University of
b) Commonwealth of
c) The name of your baby's mama?

I'm a Hokie also, along with my daughter. '75 and '05. I'm '75 (not age) if that helps.

My baby's mama would not ever get on the forum. She just asks me why I spend so much time on the computer reading this forum.

[vtbeerloverguy]

Originally Posted by retepsnikrep

The difference in the variations for the MCM programming are quite subtle but basically any MCM from a manual car of the same model 2003-2005 should work. Don't get hung up on the exact version number.

If you take the top off the mcm and find any damage or identify the relevant transistor please post some good quality pictures so we can advise further and others can also benefit.

I'm looking at honda parts dealers websites to try to find the part numbers for '03-'05 5-speed's and the part numbers appear to be identical between the 5-speeds and the CVT's within the year, but not between years. And the cost difference is a couple hundred bucks, which makes me wonder how similar they are. Is the hardware the same (within a given year) but they put different software on it depending on which transmission it has?

This is what I found:

'03 HCH1 KA5MT or KACVT
1K000-PZA-405
1K000-PZA-A02
replaced by 1K080-PZA-415

'04 HCH1 KA5MT or KACVT
1K000-PZA-415
1K000-PZA-A03
replaced by 1K080-PZA-419

'05 HCH1 KA5MT or KACVT
1K000-PZA-307
1K000-PZA-A04
1K000-PZA-A06
replaced by 1K080-PZA-315


I know it's backwards, but after I receive the replacement and confirm it's working then I'll try to fix my old MCM and take lots of pictures. Since I need my car to get to work, I'm not bold enough to try to fix it without having a backup plan. My MCM is working perfectly now with the exception of running my battery cooling fan at full speed all the time. While not ideal, at least it failed in a way that is still cooling the battery.