Hey there,
I have a 2002 civic si hatchback and I have a series of issues that I am pretty sure are the multiplex control unit. The ac wont cool, cabin lights wont turn on, emer brake light stays on, rear wiper and power locks wont work. I have checked all the fuses and I received the multiplex unit from a honda dealer online (part 38140-S3N-003) but I have almost taken the whole dash apart and I cannot find it. I have attached a photo of the schematic, and it is part number 5. Does anyone know where this is on a civic si 2002?

Thanks a ton,
Dean
http://www.hondaautomotiveparts.com/...IT+%28CABIN%29

 

The multi-plex control unit is apart of the fuse box as illustrated in the picture below. I feel sorry that you took apart the whole dash. Very unnecessary to do all of that work.

 

So it is not a separate unit? I guess I need to get the whole fuse box then? The part that honda sent me is way too big to fit into the fuse box. Thanks a lot for the great illustration.

 

And I'm having gauge cluster light problems as well as ac switch does nothing, and my speedo needle jumps all over the place, every now and again...could these problems be my multiplex? What exactly does a multiplex do?

 

bump for more info

 

Part number 5 in the pic looks like its just a braket?? The multiplex unit is part of the fuse box assy. You need illustration number 7, part number 38200-S5T-A02.

I have a 02 Honda Crv, and my brake light just came on, my ac dont work, my keyless doesnt work, power door locks dont work. I downloaded a service manual for my crv back when i got it, and i did all the trouble shooting steps and it lead to being a defective
multiplex unit. A new one from honda was $250. So I looked on ebay and found a used one for $95 shipped from a scrap yard. I didnt get it yet, but wishfully thats the problem.


I dont get it, why the **** would honda do this ****. Why dont they just keep these systems seperate. My keyless dont work, so my ac wont either, if my brake light comes on my keyless dont work, etc, etc. All new cars with crazy technology are all junk...

 

Just an update. I recieved my used multiplex unit and installed it. And it fixed all my problems.