1994 Mazda Miata¶

Frankenso Mazda Miata NA6 PnP

Frankenso options

ECU pin-out seems to be very similar to 1990 with few exceptions:

1. dedicated MAF ground

2. individual injector wiring

Plug 1¶

22 pin

pos	b pos	color	desc	type
1A		BLU/RED	Hot at all times. Room Fuse.	Input +12v
1B		WHT/RED	Main relay	Input +12v
1C		VIO
1D		WHT/GRN	Data Link Connector
1E		YEL/BLK	Check Engine Light
1F	*	*	* Extra analog input (WB O2?)	Extra Input
1G	W7 0Ohm	BRN/YEL	Coil Pack Cylinder 1&4	Output
1H	W8 0Ohm	BRN	Coil Pack Cylinder 2&3	Output
1I		BLU/WHT	Powertrain Control Module (Transmission)
1J		BLU/BLK	A/C Compressor Relay
1K		BLK	J/C? (M/T Only)
1L		BLK/GRN	Coolant Fan Relay	Output, low-side
1M		GRN/RED	Vehicle Speed Sensor	Input
1N		RED	Powertrain Control Module (Transmission)
1O		GRN/BLK	stop light switch	Input
1P		BLU/YEL
1Q		LT GRN/BLK	AC Pressure Switch
1R		YEL/BLK
1S		BLU/ORG	Heater Control Unit
1T		YEL/RED
1U		RED/BLK
1V		BRN/WHT	Powertrain Control Module (Transmission) & Clutch Switch

Plug 2¶

26 pin

pos	b pos	color	desc	type
2A		BLK	Pwr Ground	Ground
2B		BLK	Pwr Ground	Ground
2C		BLK/LT GRN	Logic Ground	Ground
2D		BLK/BLU	Logic Ground	Ground
2E	W43 0Ohm	WHT	Crank angle #1 CKP	Input, four times
2F		BLK/RED	MAF signal ground	Ground
2G	W45 0Ohm	YEL/BLU	Crank angle #2
2H		LT GRN/YEL	Data Link Connector
2I		BLK/WHT	tacho signal	Input
2J		LT GRN/RED	EGR Function Sensor	Input
2K	W49 0Ohm	LT GRN/WHT	+5 ref/TPS power	Output 5v
2L		BLU/RED	Rear Defroster relay
2M	W51 0Ohm	RED/BLK	throttle position sensor
2N	W52 0Ohm	RED/BLU	heated O2 sensor
2O	W53 0Ohm	RED	MAF signal	analog input
2P	W54 0Ohm	RED/BLK	intake air thermosensor	analog input
2Q		BLU/WHT	Coolant thermosensor
2R		YEL/GRN	Pressure regulator solenoid	Output/low side (?)
2S		BLU/WHT	Condenser Fan Relay	Output/low side (?)
2T	W58 0Ohm	LT GRN	Fuel Pump relay	Output/low side
2U	W59	YEL	Injector #1	Output/low side
2V	W60 0Ohm	YEL/BLK	Injector #2	Output/low side
2W	W61 0Ohm	BLU/ORG	idle valve control	Output/low side
2X	W62	YEL/RED	purge solenoid	Output/low side
2Y	W63 0Ohm	GRN/WHT	Injector #3	Output/low side
2Z	W64 0Ohm	GRN	Injector #4	Output/low side

== Diagram == 1990-2000 Miata System Wiring Diagrams

CAS¶

Source: http://www.rivercityroad.com/garage/cas.htm The CAS has four wires. Two are for +12 power and ground. The other two are the output signals read by the engine computer.

The signals are called SGC and SGT on the 1.8 engine. They are called called NE and G signals on the 1.6 engine. The computer can decode the position of the engine camshaft and the engine speed from these two signals. With this information, it calculates when to send spark to the spark plugs and fuel to the fuel injectors.