MCU Compatibility
Thread Starter
Registered!!
Joined: Dec 2015
Posts: 4
Likes: 0
Rep Power: 0 
Re: MCU Compatibility
Any chance I could use it to troubleshoot my gauge cluster? Speedo, tach, fuel gauge, etc. don't work and I'm trying to figure out why. It'd be nice to know if the mcu was the culprit. Or rule something out at least...
If you think a good mechanic is expensive, try hiring a bad one
Joined: Dec 2011
Posts: 32,017
Likes: 256
From: Midwest. Aiming about mid-chest
Rep Power: 518 
Re: MCU Compatibility
Wait a minute....What are you calling the MCU? The motor control unit (PCM, ECM, ECU) or the multiplex control unit (MICU)?
If you think a good mechanic is expensive, try hiring a bad one
Joined: Dec 2011
Posts: 32,017
Likes: 256
From: Midwest. Aiming about mid-chest
Rep Power: 518 Re: MCU Compatibility
Do a cluster self diagnosis first. That would make the needles all sweep and lights flash.
If a PCM burns up the gauges usually act weird, not die altogether. PCM burns up when someone leaves the alternator mounting bolts loose.
If an MICU dies there are usually many other weird electrical symptoms to go along with it: AC, locks, dome lights, warning beeper are usually all affected by an MICU failure.
The most recent one I replaced had the red BRAKE warning light stuck on on the dash.
If a PCM burns up the gauges usually act weird, not die altogether. PCM burns up when someone leaves the alternator mounting bolts loose.
If an MICU dies there are usually many other weird electrical symptoms to go along with it: AC, locks, dome lights, warning beeper are usually all affected by an MICU failure.
The most recent one I replaced had the red BRAKE warning light stuck on on the dash.
Thread Starter
Registered!!
Joined: Dec 2015
Posts: 4
Likes: 0
Rep Power: 0 Re: MCU Compatibility
The multiplexer, so MICU I guess. Ido have some other strange problems but mostly related to the cluster. It's intermittent though. When the cluster goes off, the brake light stays on. Also the backlight for the ac controls goes out. I have a spare MICU from a '04 and one from a '02 automatic (mine's a manual) that I pulled from the junkyard. Just was hoping to be able to test something before I go spend on a new cluster.
If you think a good mechanic is expensive, try hiring a bad one
Joined: Dec 2011
Posts: 32,017
Likes: 256
From: Midwest. Aiming about mid-chest
Rep Power: 518 Re: MCU Compatibility
Well that explains it better. Still not exactly compatible.
According to the parts catalog numbers, they all have different part numbers....but might be worth plugging in just to see.
DX vs. EX/LX
Auto vs. manual
Coupe vs. sedan
There's 8 different units right there.
and each year picked adds even more part numbers to those. 02 and 04 gave me a total of 16 different part numbers and I did not look at the hatchback choices.
According to the parts catalog numbers, they all have different part numbers....but might be worth plugging in just to see.
DX vs. EX/LX
Auto vs. manual
Coupe vs. sedan
There's 8 different units right there.
and each year picked adds even more part numbers to those. 02 and 04 gave me a total of 16 different part numbers and I did not look at the hatchback choices.
Thread
Thread Starter
Honda Civic Forum
Replies
Last Post
Marc23.4
7th Generation Civic 2001 - 2005
3
Dec 12, 2015 05:45 PM
MamaBear2015
6th Generation Civic 1996 - 2000
10
Dec 5, 2015 04:03 PM
