Spent some time this week trying to pin out this cluster, I can't find a wiring diagram anywhere for it. I put it in today, got it powered up - including the speedo - and went for a drive, but no speed. Next job is to find out which wire is the speed signal coming into my oem dash and tap into it; almost there
Added to my journal: I started experiencing surging/hesitation intermittently, one day it was fine, next day or later on same day surging. No cel, no codes so it was frustrating trying to pinpoint what it could be, especially with how intermittent it was; here's what I checked trying to find what it could be.
Tested upstream 02 sensor - good
Tested knock sensor – tested good but had small crack - replaced
Checked MAF sensor, cleaned
Checked all vacuum lines – all good (broke BOV nipple; repaired)
Checked grounds – all good
Checked alternator/battery voltage
Checked air filter – good
Checked fuel filter – changed
Checked IC y-pipe - good
Checked Plugs & Wires – good
Checked TPS - good
It became personal, man vs machine
and I spent lots of time going over pages from different forums and found a reference to similar problems on an JDM NSX
Basically, the boards on the MAF sensor had an issue where the solder would pull away from the contacts, I pulled mine apart and found one contact that was not soldered tight and when I'd hit a bump on our lovely roads, it would cause the issue I was having. I re-soldered it, put it back together and it is running back to it's reliable self again. After two days I can say it has been resolved.
Here's some reference pictures from my car:
MAF - remove all sealant around the top of the MAF and remove lid:
Remove metal lid:
use a small flat blade screwdriver to carefully pry on circuit boards where it meets the pins; I had movement on pin two: