# 1990 Mazda Miata [Frankenso Mazda Miata NA6 PnP](Frankenso-MazdaMiataNA6-pnp) ![Pinout](Images/frankenso_connector_miata_1991.png) 1990 1.6 US Rusefi Engine Type 41 on Frankenso ## Plug 1 22 pin | pos | b pos | color | desc | type | | --- | ----- | ---------- | ------------------------------ | --------------- | | 1A | | | hot all times, Room Fuse | Input +12v | | 1B | | White/RED | Main relay | Input +12v | | 1C | | Violet | Ignition on | Input +12v | | 1D | | | | | | 1E | | YEL/BLK | Check Engine Light MIL | Output PD5 | | 1F | | | | | | 1G | W7? | | Igniter 1 & 4 | Output +5v PE14 | | 1H | W8 | | Igniter 2 & 3 | Output +5v PC7 | | 1I | | \* | \* | \* | | 1J | W10 | BLue/Black | A/C relay | ? | | 1K | | | diag connector mode switch TEN | | | 1L | | | N/C | | | 1M | | | N/C | | | 1N | | | | | | 1O | | | stop light switch | input | | 1P | | | Power Steering SW | | | 1Q | | | AC Thermo SW | | | 1R | W18? | BLK/GRN | A/C Extra Cooling Fan Relay | | | 1S | | | Heater Control SW | | | 1T | | | | | | 1U | | | Tail Fuse | | | 1V | | | | | *** "On a 1990 - 1993 Miata, there are three coolant sensors." "On the top of the thermostat housing at the front of the engine is the 'Water Thermoswitch,' a single-wire sensor that turns the fan on when coolant temperature reaches 207°F (97°C)." "At the rear of the cylinder head is the 'Water Thermosensor.' which sends temperature info to the ECU to help it set A/F ratio." ## Plug 3 26 pin | pos | b pos | color | desc | type | | --- | ----- | ---------------- | ---------------------------- | ------------------------------------- | | 3A | W39 | | | Ground | | 3B | W40 | | | Ground | | 3C | W41 | | | Ground | | 3D | W42 | | | Ground | | 3E | | White | Crank angle \#1 | Input PC6 | | 3F | | \* | \* | \* | | 3G | | Yellow/BLue | Crank angle \#2 | Input, PA5 | | 3H | W46? | | MAP | Inp10 PA6 | | 3I | | | Tach Input | | | 3J | | \* | \* | \* | | 3K | W49 | LT GRN/RED | \+5 ref/TPS power | Output 5v | | 3L | W50 | LT GRN/WHT | M/T TPS switch | Analog input PA2 | | 3M | W51 | Red/Black | TPS signal (A/T) | Analog input | | 3N | W52 | Red/BLue | oxygen sensor | Input PC3 | | 3O | W53 | Red | VAF/MAF | | | 3P | W54 | Red/Green | IAT, intake air thermosensor | analog input, 2.7K pull-up, 3.6K? PC1 | | 3Q | W55 | BLue/White | CLT, water thermosensor | analog input, 2.7K pull-up, 3.6K? PC2 | | 3R | W56 | \* | \* | \* | | 3S | W57 | \* | \* | \* | | 3T | W58 | \* | \* | \* | | 3U | W59 | Yellow | injector (1&3) | Output/low side | | 3V | W60 | Yellow/Black | injector (2&4) | Output/low side | | 3W | W61 | BLue/Orange | Idle Speed Control valve | Output/low side | | 3X | W62 | White/Blue | purge solenoid valve control | Output | | 3Y | W63 | \* | \* | \* | | 3Z | | A/T control unit | | | ![Wiring Diagram](OEM-Docs/Mazda/1990_Miata/1990_mazda_miata_us_wiring.png) See also [Mazda ECU Technical Data](https://sites.google.com/site/mazdaecutechnicaldata/) See you - some notes on stock ECU schematics (TinyCAD format) - [https://drive.google.com/file/d/0B7l1FeMZcfisM3pHanlkWFRGQVU/view?usp=sharing](https://drive.google.com/file/d/0B7l1FeMZcfisM3pHanlkWFRGQVU/view?usp=sharing) ## Gauges Useful wires: CLT B/L Black/Blue Oil Y/A Yellow/? Turn signal Right G/W Green/White Turn signal Left G/B Green/Black ![Wiring Diagram](Images/2009-11-10_224518_tach.gif) See also [http://www.mellens.net/mazda/Mazda-Miata-1991-1993/1991_wiring.pdf](http://www.mellens.net/mazda/Mazda-Miata-1991-1993/1991_wiring.pdf)