Diagnostic Port Pinouts
 

90-93
https://www.miataforumz.com/attachme...1&d=1316179837

94-97
https://www.miataforumz.com/attachme...1&d=1316192190

99-00
https://www.miataforumz.com/attachme...1&d=1316179819


FEN = Self-Diagnosis Checker (Monitor Lamp)
MEN = Self-Diagnosis Checker (Code Number)
KLN = Self-Diagnosis Checker
TEN = Timing Lock (Grounding this locks the timing at 10°)
+B = Battery 12v
GND = Ground
SGND = Sensor Ground
FAB = Air Bag Control Unit
IG- = Tach signal from coils
TFA = Cooling Fan Relay (Jumping to GND turns on cooling fan) - Not on ‘99-2000
F/P = Fuel Pump Relay (Jumping to GND turns on the fuel pump)
TAB = Horn Relay (Jumping to GND engages the horn)
FSC = Cruise Control Module
TAT = Auto Transmission
FAT = Auto Transmission
TBS = ABS Module (AT)
FBS = ABS Module (P)
* = Blank and/or Unused


NOTE: If your miata lacks a CEL on the dash, you can jump GND and TEN and then using an LED, you can put it across B+ and FEN to read the flashes to pull the stored codes. You must use a resistor on one of the leads, in the 470ohm range.

https://www.miataforumz.com/attachme...1&d=1316195314

Note that if you short B+ and GND in the 01 diagnostics box, it will blow a fuse and you'll be stranded.

Ask Brain how I know this.

Yes, that will happen.

lol. I went to school to learn not to do that.

that's what happens when the box isn't labeled and you're "postive this pin is TEN"

i was close.

poor y8s, getting screwed on the NB! did it blow your main fuse?

no, B+ is behind the Engine fuse in cabin.

ohhh! sounds right, I think its usually battery mishaps that blue main engine fuse. like hooking them up backwards.

when you ask "did it blow my main fuse"

you mean to ask did Braineack blow my fuse.

lol, did it feel good Brain?