DIYPNP Documentation for 1991 – 1992 Mitsubishi Galant VR4

NOTE: The DIYPNPN52-K Kit has been discontinued as of 8/30/18.

1991 – 1992 Mitsubishi Galant VR4

Test Vehicle Details:

The vehicle used for drawing up these application docs was a USDM 1992 Mitsubishi Galant VR4.  All factory electronics/ignition system components are in place and the factory wiring harness is in satisfactory condition.

Other notes:
Stock air flow meter removed.
GM open element IAT installed after intercooler and before throttle body.

[ARCHIVED] What to buy:

1- DIYPNPN52-K Kit (DISCONTINUED)  This is the main DIYPNP Kit including the Nippon Denso style 52-pin connector and all components, case, etc.

1- Tuning Cable  This is the same DB9 serial tuning cable used in other MegaSquirt applications.
1- USB Adapter  This is a DB9 serial to USB adapter.  The adapter is needed when the laptop or PC you are using does not have a built in DB9 serial port.
1- StimPower  This is a power supply that is normally sold to power a stimulator, but another use is it can be plugged directly into the DIYPNP mainboard to power the ECU directly, allowing you to load the basemaps and do limited testing on the ECU prior to installing the ECU in your vehicle.  It is particularly nice to be able to flash the firmware and load your configuration on the bench instead of in the vehicle, and allows for less risk of damaging something on the vehicle due to incorrect settings.
1- PNP_IAT-A or PNP_IAT-S AFM/MAF Delete kit. This is a simple kit with an IAT sensor, wire pigtail, crimp pins to poke into the AFM Connector to run the signal back to the ECU, and a steel or aluminum bung (hence the -A and -S in the part numbers).  Perfect for getting rid of a restrictive AFM/MAF with your DIYPNP install.

What tools you’ll need: Soldering Iron, Solder, maybe some desoldering braid in case you make a mistake.  Small phillips screwdriver.  That’s about it.

What tools you’ll need:

Soldering Iron, Solder, maybe some desoldering braid in case you make a mistake.  Small phillips screwdriver.  That’s about it.

Startup Maps

Base Configuration .msq files to help you get your car fired up safely and quickly.  Ready to tune.

We’re including these maps prior to showing you how to jumper your DIYPNP up.  There’s a reason for that.  The base ignition settings contained in these maps should be loaded on your DIYPNP before you power your car up (with the key) with the DIYPNP installed.  This is to prevent damage to your ignition system in case the default settings are not correct for your vehicle. Note that you can power up the DIYPNP off the vehicle on a power supply connected to the power jack next to the DB15 connector.

So here’s our recommendation–  After you complete basic assembly, Power up your DIYPNP one of two ways.  Either plug a Stimulator Power Supply into the front panel of the box (the easiest way), or, start the Jumper Section below, but only connect the power and ground wires to start with.  That way you can plug the DIYPNP into your factory wiring harness and safely power it from your car.  The third option, if you’ve fully assembled and jumpered your DIYPNP already, is to unplug your coils from their power connectors before plugging the DIYPNP into your factory harness and powering it from there.

Then and only then, you can flash the firmware on your DIYPNP to the MS2/Extra firmware if you haven’t already, and then load the startup map provided to help you get your vehicle started.

Click Here to Download Startup Maps for this Vehicle

Once the vehicle is started, you will need to use the MS2/Extra manuals to set the base timing and begin to tune the vehicle!  This is critical!  Do not drive an untuned vehicle!

DIYPNP Jumper Configuration

This section will cover the standard, basic jumper configuration required to get the vehicle running using your DIYPNP.

Vehicle Information

Market: USDM
Make: Mitsubishi
Model: Galant
Year: 91 – 92
Engine: 4G63
Transmission: Manual
Trim: VR4

System Information

Main Board: DIYPNP v1.5
Minimum Code Version MS2/Extra 3.0.3T

Edge Pin Connections

Main Adapter
VR2 IN + A3
INJ1 B8, B18
INJ2 B9, B17
12V C4
IGN1 B15
IGN2 B14

Pull Ups

Connection Resistance Voltage
OPTO+ 470 Ohm 12V
VR2 470 Ohm 12V

High Current Drivers

Output Enabled To Pin

Knock Circuit

Enabled Sensor + Sensor –

I/O Circuits

Circuit Input From Out Pin To Purpose
Relay 1 C1 B3, B6 Main Relay 12V
Relay 2
Input 1
Input 2

Miscellaneous Jumpers

On Off


Stepper idle valve connections:
Stepper output 1A to B2
Stepper output 1B to B1
Stepper output 2A to B11
Stepper output 2B to B10


Ignition Settings

Spark Mode 4G63
Trigger Angle -3
Oddfire Angle
Use Cam Signal
Ignition Input Capture Falling Edge
Spark Output Going High (Inverted)
Number of Coils Wasted Spark
Dwell type Standard Dwell
Cranking Dwell 6.0
Cranking Advance 10
Maximum Dwell 3.1
Maximum Spark Duration 0.7
Trigger wheel arrangement
Trigger wheel teeth
Missing teeth
Tooth #1 angle
Wheel speed
Second trigger active on
and every rotation of

Other Changes/Considerations

This section will cover changes that need to be made to the DIYPNP that go beyond the standard I/O jumpering, such as intake valve butterfly activation, on/off VVT activation, or other customizations to address the specific needs of a vehicle.

12V Supply to ECU

To bring switched 12V to the ECU you will first need to take control of the main relay.  Jumper from connectorboard C1 to the “IN” of one of the relay circuits.  Jumper from the “OUT” of the same relay circuit to both B3 and B6 on the connectorboard.  The resulting output from the main relay will then be brought to the ECU by jumping connectorboard C4 to 12V on the main board.

Stepper Idle Motor Control

The stepper idle control motor uses 6 wires.  There are two 12V power wires and the four coil operation wires.  We will be leaving the 12V wires connected for this installation.

  • Stepper circuit output 1A connects to connectorboard terminal B2

  • Stepper circuit output 1B connects to connectorboard terminal B1

  • Stepper circuit output 2A connects to connectorboard terminal B11

  • Stepper circuit output 2B connects to connectorboard terminal B10

In addition to these four output jumpers, you will want to jumper from PT6, PT7, and PB4 (up near the DB15) on the main board to the stepper circuit on the connectorboard.  Jumpers for 12V, 5V, and GND will also need to be run from the main board to the connectorboard.

  • If the valve works in the opposite of how you expect, you may reverse the PT6 and PT7 jumpers so they cross over from PT6 to PT7 and PT7 to PT6 rather than run straight through from PT6 to PT6 and PT7 to PT7.

Extra Accessories

This Galant VR4 did not have operational A/C or factory boost control.  These figures are untested but taken from the vehicle electrical wiring diagram.

  • For the A/C:

    • Jumper from connectorboard A18 to “IN” on one of the unused relay control circuits

    • Jumper from “OUT” of the same relay control circuit to connectorboard B4

  • For the boost control:

    • Jumper from PA0 near the DB15 to “IN” on the boost control circuit

    • Jumper from “OUT” of the boost control circuit to C6 on the connectorboard

    • It may be possible to use the factory control solenoid, or we offer an alternative solenoid in our web store.

Sensor Calibration

  • This vehicle does have a variable TPS.  You should calibrate it properly from TunerStudio in the ‘Tools’ menu.  Choose ‘Calibrate TPS’.

    • Make sure the engine is off, and the key is on.

    • With your foot off of the throttle, click the ‘Closed Throttle ADC Count – GET CURRENT’ Button.

    • Put the throttle to the floor.  With your foot fully depressing the throttle, click the ‘Full Throttle ADC Count – GET CURRENT’ Button.

    • Click Close.

  • Calibrate your CLT Sensor and IAT Sensor.  The bias resistor value is 2490 ohms.

    • Again from TunerStudio, click ‘Tools > Calibrate Thermistor Tables’.  Make sure ‘Coolant Temperature Sensor’ is selected at the top.

      • For the CLT, use the following table:

        Temperature    F Resistance In Ohms
        68 2500
        75 2082
        176 300
    • Enter these values, and click ‘Write to Controller’.

    • Since this is a turbo car the IAT sensor will need to be installed after the intercooler and before the throttle body.  We used the GM open element IAT.

      • For the IAT, use the following table with a bias resistor setting of 2490 Ohms.

        Temperature    F Resistance In Ohms
        48 7000
        87 1930
        146 560
    • Enter these values, and click ‘Write to Controller’.  Now click Close to Exit.

  • Finally, you should calibrate your O2 Sensor to the ECU.  To do this, click ‘Tools > Calibrate AFR Table’.

    • Choose your O2 Sensor from the list.  Choose Narrowband for the stock O2 Sensor.  Or select your wideband and the proper configuration of said wideband from the drop-down list.

    • Click ‘Write to Controller’.  Once finished writing, click ‘Close’.

Deleting the MAF

This is completely optional of course… but if you’d like to rid yourself of that pesky and restrictive Air Flow Meter you need to remember that the stock IAT sensor is inside that housing.

IAT Sensor:

Simply wire a GM Open Element IAT Sensor into your factory wiring harness at the AFM connector.  You can poke wires into the AFM connector, or you can cut and splice.  Looking into the wiring harness connector that plugs onto the AFM with the two location notches to the top and the three to the bottom, connect one wire of the GM IAT to the far left terminal and connecto the other wire to the 5th terminal, counting from the left.  Both of these terminals are colored red in the image below.

 MAF Delete Diagram

You  may poke the wires into the MAF connector if you wish, or cut and splice.  There are only two wires to worry about with the IAT sensor and it does not matter which way they are connected as the sensor does not have a specific polarity.

The wires should then be folded down over the edge of the MAF connector, and the whole assembly firmly and cleanly wrapped in high quality electrical tape sealing it up. 3M makes some good stuff that can handle the temps found in engine bays– read the specs.

Read the Manuals, You are Responsible for your own results!

This Application Doc is intended to assist you in your DIYPNP DIY EFI Installation.  We’ve done a fair amount of research, and actually tested on a similar vehicle to help ensure we can provide the most accurate information possible to make your installation go as smoothly as possible. That said, there are certain things you could do incorrectly, or certain things you could change up, that could cause you to run into issues.  Our tech support department will be glad to assist you working through any issues you might have, please contact us and give us that opportunity and we should be able to work things out for you.

Startup Maps included/attached to this Application Doc is intended only to help you get your engine started so that you can properly tune your engine.  The map will be setup properly for a stock vehicle matching the year/make/model/trim in the ‘Test Vehicle Details’ section at the top of this page.  If you have made any changes to your wiring, your ignition system, or other related components, this map may not be ideal for your vehicle.  You will then need to check and confirm the appropriate settings and properly configure your DIYPNP EMS for your altered vehicle.  Some maps offered may be more completely tuned that others, some may be just setup enough to get the car to fire up and idle with a little help from the throttle.  That’s when the tuning begins.

In short– We’ve provided you with the building blocks for an incredible EMS.  You are however responsible for the implementation and your own successes or lack thereof, but rest assured that we’re here for you and we’re going to do everything in our power to make sure your project is a success.

For more information on configuring and tuning your DIYPNP EMS, and for information on adding and tuning custom MS2/Extra features, read up at  In fact, everyone implementing this system should read that manual from front to back if you really want to harness the power of the DIYPNP EMS.

We’d love to hear your feedback on our DIYPNP Application Docs.  Click Here to offer feedback/suggestions!