Welcome to our ME ECU quick start guide. This guide follows the basic installation of an ME ECU and is applicable to 90% of installations. For a comprehensive guide, or for anything not covered here, please see Motorsport Electronics full install guide below.
https://docs.google.com/document/d/1VeizwbWkuNf3MpPQMhfjLeOFe0Q7X0oTUbhhh898Aqc/edit?usp=sharing
Before Plugging in
- IMPORTANT – For NA/MK1 only – Remove ST Sign Fuse from engine bay fuse box.
- For NA 1.6 only – install your VTPS to throttle body (if using)
- After vTPS installation set both ECU board dip switches to ON (#2 on the image above)
- For NA/MK1 only – Install IAT (Intake air temp) sensor somewhere in your intake (if using)
- We recommend using the following adaptor – https://bofiracing.co.uk/performance/ecu-electronics/wiring-connectors/diy-efi-maf-delete-iat-install-harness-for-mazda-mx-5-na/
- Install Injectors (If using)
- For installation instructions see https://bofiracing.co.uk/wp-content/uploads/2017/10/Fuel-Injectors-640cc-PnP-1.pdf
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- Install wideband sensor into the downpipe and run the cable into the interior through one of the firewall grommets on the passenger side in the engine bay
- CAUTION wideband sensors are very sensitive and can easily break if hit on a hard surface. Care should be taken when installing this sensor to carefully insert it into the downpipe without it hitting anything on the way down
Plugging your ECU into the car
IMPORTANT – Maximum care should be taken when handling the ECU.
- Static build-up from clothes or your environment can damage the board.
- Oils and dirt from your fingers or environment can damage the board.
- Only hold the PCB board by its corners/edges and never touch any of the electrical gubbins in the middle of the board
- Install on a conductive and earthed workspace
Installation Procedure
- Disconnect the negative battery terminal
- Ensure ignition is switched off
- Pull up the carpet of the passenger footwell to find stock ECU under a bolted-down kick plate
- Remove the factory ECU holder & unplug factory ECU wiring loom
- Remove the top cover of the ECU holder. Some NB cars have security bolts on each corner of the ECU case, these will need drilling out
- Test fit the ME ECU in the case and mark the side of the case where you want to run the USB, Vac line and wideband cables. (#3, #4 & #6 on the image above)
- Remove ECU from case & drill some holes where you’ve marked and ensure each cable can fit into the ECU case
- Install ME ECU into the case
- Install 3mm vacuum line to the ECU by connecting one end to the intake manifold and the other end to the MAP Sensor (#3 on the image above) running the line through the grommets in the firewall
- We recommend securing the vacuum lines to the MAP Sensor with a small cable tie
- Plug in the USB & wideband through the side of the case
- Reinstall top cover
- Plug your ECU into the chassis and reinstall but DO NOT ATTEMPT TO START
- Reconnect battery
- If you’ve opted for an ME221, you’ll need to wire in the wideband controller to the ECU now.
Plugging your ECU into a laptop
Before first startup, you’ll need to configure your ECU using MEITE tuning software. On a Windows laptop, download and install MEITE from the “PC Software” tab here:
https://motorsport-electronics.co.uk/support/
Once installed, plug the USB from your ECU into the laptop, switch the car’s ignition on, wait 10 seconds, then go to ECU > Connect in MEITE. The bar in the bottom right should go green.
If your ECU isn’t now connected, try the following steps
- Ensure the USB cable is securely plugged into both the ECU and your laptop
- Restart your laptop and re-open MEITE
- Ensure the battery is connected and charged
- Try a different USB port on your laptop
If this all fails, give us a call on 01480 759 200 or send an email to [email protected] and we’ll do our best to help
ECU Configuration
Loading a Basemap
Before touching any settings in the ECU, you’ll need to load a basemap that is closest to your use case. To do this, go to File > Load basemap.
A new pop up will appear and you’ll need to follow the tree down to pick your required map. For example, if you have got a stock 1994 NA with an ME442, you’ll go to
Base maps > ME442 Plug in > MX-5 > FW (current firmware number) > MX58995 1.8 OEM
Throttle Calibration
The first thing to do is to configure your throttle so the ECU knows what is 100% open and what is fully closed. Go to ECU > Throttle Calibration and follow the steps to configure.
Intake Air Temp Calibration
To configure your intake air temp sensor, go to the search bar in the top left hand side of MEITE, Search “IAT” and double click on “IAT HRT”. A new window will pop up and you’ll need to enter the following information into the table.
| Predicted V (Volts) | T (Celcius) |
| 0.389 | 120 |
| 0.616 | 100 |
| 0.992 | 80 |
| 1.486 | 63 |
| 1.991 | 50 |
| 2.446 | 40 |
| 2.835 | 32 |
| 3.179 | 25 |
| 3.419 | 20 |
| 3.648 | 15 |
| 3.862 | 10 |
| 4.057 | 5 |
| 4.231 | 0 |
| 4.463 | -8 |
| 4.71 | -20 |
| 4.915 | -40 |
Fuel Pump operation (NA ONLY)
If you are still using the OEM MAF sensor your fuel pump should work correctly. If you’re now using an aftermarket IAT, you’ll need to follow the following instructions. This can be confirmed by switching the ignition on (but NOT the engine) and listening for a 2-3 second buzz from the fuel pump.
ME221
Run a wire from the FP pin in the engine bay diagnostic box to pin 2T in the ECU.
ME442
Assign HB OUT+ to Fuel Pump in IO setting in MEITE.
Injector Calibration
If you’ve installed larger aftermarket injectors you’ll need to input the deadtimes that the manufacturer has provided. You’ll normally find you have both a 3.0 BAR and 4.0 BAR set of data. If you have a 1989 to 1997 NA, you’ll need to use the 3.0 BAR data, if you have a 1998-2005 NB, you’ll use the 4.0 BAR data.
To input dead times, go to the search box in the top left and type “dead time”. Double click on the option “Inj. Dead Time” and a new table will appear. Enter the data you’ve been given here.
If you don’t have the data to fill all 16 boxes, repeat the last line all the way down as shown below.
If you’ve chosen to go for our own set of EV14 injectors, the deadtimes and full installation manual is here:
https://bofiracing.co.uk/wp-content/uploads/2017/10/Fuel-Injectors-640cc-PnP-1.pdf
Setting base timing
To do this, you’ll ideally need two people. One to crank the car and the other to hold a timing gun/timing light.
In MEITE, go to the START tab in the top left and find the box called “Ignition Driver”
Inside ignition driver, set the mode to wasted spark (or set to the relevant mode if you’re changing this) and set Fixed Fire (10 Adv) to yes.
This locks your engine’s timing at what the ECU thinks is 10 degrees TDC.
After this, you’ll need to provide power to the timing light and plumb this into the ignition lead on cylinder 1 (the closest one to the front)
Get your helper to sit in the car and crank the engine while you hold the timing light at the lower engine pulley. As the engine cranks, the timing gun will fire and you should see the markings on the engine pulley align with the timing marks on the plastic cover.
If your left pulley mark doesn’t align with the 10-degree mark, you’ll need to change the trigger offset in MEITE.
Before doing this, we recommend turning the injection driver off to prevent soaking your plugs in fuel. Go to the START screen, find injection driver and change the mode to OFF.
To change the trigger offset, In the START screen find the “Engine Driver” panel and locate “Trigger Offset”
*Depending on your chassis type, the trigger offset number may be wildly different to 106, the 106 trigger offset in the photo above is just for demonstration*
If your current timing mark is too high, I.e. to the left of the 10 mark, you’ll want to decrease the trigger offset number, if your mark is too low you’ll want to increase this number. If your timing is way out, you’ll want to increase this number in steps of 5 to bring it back into line.
The goal is to change that trigger offset number so that the left-hand side pulley mark is the closest to the 10 mark as it can be. It may take a few goes of cranking, looking at the timing mark and adjusting the trigger offset to get it dead on.
Once all your marks line up, remember to find your injection driver and change the fueling mode back to “batch” (or Fully Seq if you’re using this) and to also change the ignition driver back to “Fixed Fire (10 Adv) to “No”.
First-Time Startup
If you’ve loaded a basemap, set all your required calibrations and your engine is in time, it’s time to try a proper start.
- With the ignition on and MEITE connected, check that:
- Your MAP sensor is reading around 98-100 KPa at sea level
- Battery voltage is 12+
- Engine coolant and intake air temperatures are reading sanely
- The TPS goes from 0 – 100% when pressing the throttle
- Rectify any issues with this list before progressing
- Switch the ignition off and back on, when switching it on you should hear a slight hum from the fuel pump for 2-3 seconds.
- Crank the engine with a bit of throttle applied, it will likely take more cranks than usual to catch but after a few seconds, the engine should burst into life.
After this, you’re done! Your ECU is loaded with a basemap and is ready to be driven to a tuner. We don’t recommend spending any longer on a basemap than is absolutely necessary and it’s important to resist the urge to drive hard until it’s fully tuned.
If you are cranking but it won’t catch, go to the diagnostics tab in MEITE and press “Start” to start logging. After a few cranks, go back and stop the diagnostics and see if you are getting a clear, full sync line. If not, there is a timing sensor issue somewhere in your engine.
If you’re having trouble with any of these steps then feel free to send an email to [email protected] or give us a call on 01480 759 200 and we’ll be on hand to help.
