It has been on my mind for a while to learn how to tune a car engine. I own a post-facelift 2000 Nissan Micra K11 that I can experiment on that I can experiment on. So I tried it.

I bought ECUmaster EMU Classic set, that contains wires, electronic valve and a Bosch LSU 4.2 Wide Band Oxygen sensor. Since I don’t plan to put a turbo in it, the valve is left unused. Maybe it will be useful to mount nitrous in the future, who knows. I’m all for crazy ideas like that.

I planned to salvage the ECU plug from another factory ECU I bought. I had a happy accident because I ordered the wrong one first (pre-lift), but in the end I used it as an enclosure.

So this type I used as an enclosure: inside

And this is the type I desoldered the plug off of: inside

It took a while to get all the wiring correct, after plowing through schematics and some trial and error, I managed to get it done. Already crimped wires from the set made the job a bit quicker.

So, here I present the post-facelift Nissan Micra K11 MOTRONIC ECU to ECUmaster EMU Classic wiring:

NISSAN ECUMASTER NISSAN DESC ECUMASTER DESC
78 B4 Coolant Temp Sensor CLT In
12 B5 ?goes to front o2 sensor? WBO Vs
16 B7 CKP Sensor Primary Trigger
73 B12 Throttle Pos Sensor Signal TPS In
44 B15 CMP Sensor Camsync In #1
52 B16 Spark Plug No.4 Ignition Coil #4
6 B17 GND ECU GND
14,11,43,71 B18 GND Sensor GND
77 B21 MAF IAT Signal IAT In
46 B23 Throttle Pos Sensor 5V +5V Supply
34 B24 GND Power GND
2 G2 IACV-ACC Valve Coil 1 Stepper Motor #1
29 G3 IACV-ACC Valve Coil 2 Stepper Motor #2
27 G5 ECM(Main) Relay AUX 3
4 G6 Injector #4
3 G7 Injector #1
51 G8 Ignition Coil #1
25 G9 Ignition Coil #3
1 G13 Fuel Pump Relay AUX 2
32 G15 Injector #2
24 G16 Ignition Coil #2
28 G17 Power GND
26 G18 Power +12V
18 G20 AUX 4 / Tacho
22 G21 Cooling Fan AUX1
31 G23 Injector #3
55 G24 Power GND

Here’s the ECUmaster EMU Classic pinout for reference: emu-pinout

Just so you know, I disconnect the battery when the car is parked. It may be better to connect Power +12V to some other pin than 26 to power the ECU only when needed. Also, the Wideband Oxygen sensor is connected externally.

Anyway, I tried packing it up neatly in the enclosure: inside-cables inside-view

And that’s how it looks like fully assembled. The ECU plug is on top simply because it did not fit into the front nor on the side. I may design and print a better housing in the future (yeah, of course), but for now that will do. exterior-view

But that’s only the hardware. I got it running and did road tuning for a couple days. I tune by throttle position, not MAP nor MAF data. That’s because the next step will be adding ITBs to the engine, i wanted to stay by the simplest method.

Car drives fine, just to be on the safe side I put there a rather rich map around AFR 13.0. It idles very very rich, around 10.0, as its hard to tune around low RPM and low throttle values, so I left it like that.

Here’s the ecumaster map if you are interested: ⬇ micra.emu

You can treat it as a reference or just try and give it a go (at your own risk). Remember, there’s no guarantee you won’t break anything. It works on my car, doesn’t mean it will 100% work on yours.

If you decide to use this ecumaster map, please disconnect IACV valve first, it’s misconfigured and pulls a lot of current on standby. I may fix it at some point, but for now it is what it is. It’s not needed, the engine idles anyway so I don’t care all that much.

The ignition map is very basic: ignition-table

The VE map is more polished: volumetric-efficiency-table

This tune is by no means perfect. I don’t actually know what I’m doing, this is my first time. I just want to share this achievement, and hopefully it will make the standalone ecu connection a bit easier for someone. If this article helped you in any way, I’ll be very happy to hear from you. Feel free to contact me by any means linked on the main page.

Thanks for stopping by!

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