MS2-Extra Miata Manual

Only for use with the MS2-Extra code (HC9S12C64 based microprocessor - MS2 Daughter Board)

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NOTE: Please ensure you have one of these daughter boards inside your ECU before continuing. If you have a black microprocessor, then you have an MS1 and these manuals are NOT for MS1 see here for MS1-Extra Manuals

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Please Note:

All of these instructions / diagrams are to be used at your own risk, like most things there is more than one way to do the same thing, what we have tried to do is to offer a method that we have tested or that others have tested for us. No warranty expressed or implied.

Use at your own risk.
If you do have any suggestions or settings that work please let me know Philip.Ringwood(at)

Main Index of MS2-Extra Manuals

Layout of Components -- Suggested Supply points -- List of common components and part numbers

99-05 Miata

Internal Wiring for Crank Sensor -- Internal Wiring for CAM sensor -- Settings

Note that the crank layout shown is slightly inaccurate as the teeth are not actually evenly spaced, the ECU allows for this.

V3.0 Internal Wiring V2.2 See HERE
Input Mods for crank sensor (See HERE for cam sensor wiring)

Output Mods for V3.0 PCB
For more options on Spark Outputs see HERE

V2.2 Internal Wiring
Input Mods for crank sensor (See HERE for cam sensor wiring)

Output Mods for V2.2 PCB


For more options on Spark Outputs see HERE


Second Trigger Input (cam sensor)

Second Hall Sensor Circuit - this needs to be built for Both V3.0 and V2.2 Boards.

Cam sensor input on pin3 of the DB37 connector on a V3.0 PCB
Cam sensor input on pin29 of the DB37 connector on a V2.2 PCB



Microsquirt V3 Wiring

For Microsquirt, no internal modifications are required.
Connect the crank sensor to VR1-. Connect the cam sensor to VR2-. Leave VR1+ and VR2+ unconnected and tape them up. See here. You may need the in-loom pullups (unsure.)
Connect IGN1 to channel 1 on the ignitor. Connect IGN2 to channel 2 on the ignitor. See here.



You must set number of cylinders to 4.

If using BIP373 for direct control over the coils then set Spark Output to Going High (Inverted) and set dwell to Standard and 3.2mS as Maximum. Also set 5.0mS as Cranking Dwell.

Spark outputs come on D14 and D16, see HERE for options on driving the coils.

If you have a question, comment, or suggestion for this FAQ please post it on the forum.

No part of this manual may be reproduced or changed without written permission from James Murray, Ken Culver and Philip Ringwood.