Haltech Plug'n'Play Adapter Mod
 

Hi,

earlier today, I modified my adapter to be able to use the Check Engine light, Brake switch, Power Steering switch, Clutch switch, and a couple of weeks ago I also wired the ac fan with the main fan.

my car is 1994 NA Miata 1.8, so this might be different between ecu's. Everything is working except the clutch switch I tried different AVI's and SPI to see if that would make a difference it didn't make me think the diagram I was using is not the correct one, i might check for continuity later between the switch and the ecu connector to confirm.

i was thinking of wiring in Evap and Fuel pressure solenoid but decided not to since i might use the inputs for oil pressure and oil temperature sensors.

Black - AC Fan/Main Fan -1L - 2S

Yellow - check engine light - 1E - A31 step1 P1

Red - brake - 1o - B20 AVI5

Purple - powersteering - 1P - A16 AVI2

White - Clutch - 1V - B7 SPI4


https://cimg2.ibsrv.net/gimg/www.mia...45f5f549cd.jpg

Hope someone finds it helpful.

These were all enabled on my VVT setup out of the box - didn't know there were differences. Good help for people that don't have them.

This is good stuff. Someone from haltech needs to look at this though and maybe revise the board and maybe add some jumpers for the AC to work for 1.8 and at least CEL. I have an IO12 so I'll run my brake and clutch to that -maybe tap into the board and run a Deutsch and save my native inputs for DBW stuff.

There is a slight delay on IO read write times so bear in mind what you're using it for. If clutch is for launch control, flat shift etc - it may be a factor although possibly not.

Nice! Will have to consider a couple of these.

This is a great mod!

Tried it on my 1.6 with clutch switch and check engine light but could not get either to work because 1.6 is weird

Check engine light: I think it expects a analogue 12v for light on but Haltech can only output digital switched signals, so the dash makes a weird whirring noise when you active the light. They do have a signal conditioner for this but you gotta do more wiring.

Clutch switch: Normal AVI signal but it also mixes in if youre in gear. Only useful if you want to know if you're in gear with clutch depressed. Maybe if you short the connectors at transmission it will be better

I believe 1.6 uses a different pinout for check engine light, I marked in blue the other two possible pins.

active state and drive type both should be low in haltech

and I don't have any weird noises with check engine light, it works fine on my car

https://cimg8.ibsrv.net/gimg/www.mia...64feb3e65e.jpg

Thank you, will try that latter
If there's enough interest and resources, maybe we can pull in resources and print our own PNP board?

Or at least submit our findings to haltech to see if they update their design