There's no difference in function between SGND and GND. They are both grounds, one to the frame, one to the engine block.

Both cause the TEN pin back at the ECU to drop from, floating high at, 12v to ground. This tells the ECU to lock the timing at 10° and to idle at 850RPM. If not, you need to adjust the CAS and/or Throttle speed screw to make this a reality.


I'll list all the changes and wires in each model year's Diag. port, but I don't have the pinouts.

 

1994 Port:

FEN - YEL/BLK - ECU pin 1E
MEN - WHT/GRN - Self-Diagnosis Checker (Code Number)
TEN - LT GRN/ YEL - ECU pin 2H
+B - WHT/RED - ECU pin 1B - 12v
GND - BLK - GND
FAT - RED - Auto Transmission
TAT - WHT - Auto Transmission
FAB - RED - ??? - Air Bag Indicator Light
IG- - BLK/WHT - Tach Singal
TFA - BLK/GRN - Fan Relay
F/P - LT GRN - Fuel Pump Relay
TAB - GRN/ORG - Horn Relay

1995:
FAB - BRN - Air Bag Indicator Light
FEN - YEL/BLK - Self-Diagnosis Checker (Check Engine Light)
+B - Wht/RED - battery 12v
MEN - WHT/GRN - Self-Diagnosis Checker (Code Number)
TEN - LT GRN/ YEL - ECU pin 2H
F/P - LT GRN - Fuel Pump Relay
TFA - BLK/GRN - Fan Relay
TAT - WHT - Auto Transmission
FAT - RED - Auto Transmission
IG- - BLK/WHT - Tach Signal
TBS - WHT/BLK - ABS Module (AT)
FBS - WHT/BLU -ABS Module (P)
TAB - GRN/ORG - Horn Relay
GND - BLK - Ground

1996-97:
FAB - BRN - Air Bag Indicator Light
KLN - WHT/BLK - Self-Diagnosis Checker (Code Number) Same as MEN
+B - Wht/RED - battery 12v
IG- - BLK/WHT - Tach Signal
TEN - LT GRN/ YEL - ECU pin 4L
F/P - LT GRN - Fuel Pump Relay
TFA - BLK/GRN - Fan Relay
TBS - WHT/BLK - ABS Module (AT)
FBS - WHT/BLU -ABS Module (P)
GND - BLK - Ground

As you can see, they all have the same functions. If you dont have ABS or A/T tranny, you wont have the same number, but all in all they are identical throughout the years like I said. Mazda's Self-Diagnosis Checker Tool plugs into these - so they are standard positioning throughout the model years.

 

i'll be making a universal single pinout we can all reference. but its almost lunch time, so it has to wait.

 

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