Table of Contents

Running a 2G DSM ECU in an EVO8

NOTE: THE INFORMATION ON THIS PAGE IS DATED. THE INFORMATION BELOW IS BASED ON DOING YOUR OWN WIRE SWAPS USING A PLUG-N-PLAY HARNESS ADAPTER. WE NOW PROVIDE A MODIFICATION SERVICE TO MAKE A 2G ECU PLUG-COMPATIBLE WITH AN EVO8 HARNESS. WHEN USING A 2G ECU THAT'S BEEN MODIFIED LIKE THIS, MUCH OF THE STUFF LISTED BELOW CAN BE IGNORED.

This used to be a popular swap for a while back when the EVOs were new. The interest seemed to die down a bit as guys started playing around with ECUFlash and EVOScan. But for some reason, we're getting more and more requests for this information lately.

So I thought I'd put this page up to help guys get the ball rolling.

FWIW, I run with a 2G ECU in my own daily driver EVO8 using the same information below. It all works very well. Now that the fans have been addressed (see below), I have absolutely no problems driving the EVO8 on a 2G DSM ECU. It drives just as well as it does on the stock ECU.

Wiring swaps

Obviously, you need to swap a few wires around on the ECU harness. This is the list of the main things that need to be re-ordered.

Evo harness → 95-97 DSM ECU

22 → 8 Swaps Fuel pump relay and AC relay control
8 → 22

10 → 23 Inverts coil control for proper firing order
23 → 10 (LEAVE 10 AND 23 ALONE IF YOU'RE USING A 97 ECU…DO NOT SWAP)

32 → 20 Moves condensor fan control to ECU (NO LONGER RECOMMENDED)
34 → 21 (NO LONGER RECOMMENDED)
NOTE: Before wiring pins 32/34 to 20/21, read the fan control section below for a different approach that works better.

40 → 13 Moves Cam and Crank sensor Ground supply

43 → 91 EVO clutch wire to feed NLTS

58 JUMPER TO 89 Do not swap, splice 89 (crank signal) to 58 (tach input) for proper tachometer operation.

37 Cut this wire. It provides the ECU with a power steering pressure switch indication. This is used to raise idle when you turn the steering wheel. But it causes more problems than anything else when running a 2G DSM ECU. Just cut it. It's not needed. I have no dips in idle when turning my steering wheel with this wire cut.

56 Cut this wire, run a wire from 56 at the 95 ECU to pin 1 at the OBD2 port in the car (note that the image is of the OBD2 connector in the car). Cut pin 1 wire at OBD2 port, do not splice this in. You want the 95 ECU to be the only thing connected to this pin on the OBD2 port.

Patch harness

By all means, use a patch harness when doing the swaps mentioned above. It's SOOO much easier to do this while working at a table inside the house/garage than it is under the dash on your back. It's a little pricey, but well worth it. Some sample shops are below. I'm sure there are plenty of others.

Mach V patch harness
Lancer Shop
Modern Automotive Performance

Known issues and work arounds

Fan control

Until just recently (Nov 2010), fan control operation with a 2G DSM ECU in an EVO8 has been a little annoying. The fans basically just ran all the time any time the ignition was on.

Radiator fan notes

The EVO8 radiator fan is powered by a separate fan control module that expects to receive a pulse-width modulated signal from the main ECU to control fan speed. The 2G DSM ECU does not do this. The 2G DSM ECU only has two simple on/off outputs to control the low and high speed operation of the main radiator fan.

So when running a 2G DSM ECU in an EVO8, the main radiator fan just kicks into a fail safe mode and runs all the time. This can be a bit annoying.

Condenser (A/C) fan notes

Condenser fan operation was a little sketchy too because the EVO8 configuration expects the ECU to control both the low and high speed operation of the condenser fan, but the DSM ECU (in factory form) only controls the high speed side of things.

Solution

Wiring changes

Make the following wiring changes to your EVO8 adapter harness, if you haven't already done so.

Evo harness → 95 ECU

21 → 21 Connects the DSM's “low speed” output to the EVO8 fan control module

32 → 20 Connects the DSM's “high speed” output to the EVO8 condenser fan's low and high speed inputs
34 → 20

Code changes

Now we need to tell the DSM ECU to do three things differently.

  1. Invert the operation of the low speed radiator fan output (because the EVO8 fan control module expects an “active high” signal)
  2. Activate both the DSM outputs (low and high) any time either one was supposed to be activated
  3. Activate the fan outputs when the A/C compressor is running

You can do that with some custom direct access files. Download these files:

evo8-fan-ctrl.properties ac-fan-2g.properties

Save each into the following directory:

Windows XP:
C:\Documents and Settings\<username>\ecmlink\resources\records

Windows Vista/Windows 7:
C:\Users\<username>\ecmlink\resources\records

Linux/Mac:
$HOME/ecmlink/resources/records

The directory should already exist, so if it doesn't, you may be looking in the wrong place.

Once you have these files installed, bring up or restart the ECMLink application. When you connect to your ECU, you'll have two new direct access entries. Go into each of these and follow the instructions at the bottom of each panel to set the cell values to appropriate values. Do this CAREFULLY as you are basically making direct code changes to the ECU code base!

Once that's done and you have verified the wiring above is 100% correct, you should be all set to start it up!

Idle control

The EVO ISC motor must provide more airflow per “step” because default operation with a 2G DSM ECU results in idle surges as the car starts to move. You can disable this using the patch listed below (you'll want to grab the moving idle disable file towards the bottom).

Custom Direct Access Files

You may also find that having the power steering pump signal connected to the ECU can cause crazy ramps up in idle too. To “work around” that, simply disconnect the wire leading to the pressure sensor on the power steering pump. That way the ECU will simply never “see” this signal and won't respond to it.

Injector scaling and default timing/fuel maps

The stock 2G DSM maps were only calibrated by Mitsubishi up to about 14-15psi. The stock EVO8 maps were calibrated a lot further out and with a nicer “shape” to them. We provide full details on how to configure ECMLink for EVO8 operation here, including new timing and fuel maps copied directly from the EVO8 ECU.

EVO8 V3 Config Settings

Idle switch and TPS

You must simulate the idle switch via DSMlink since the Evo does not use an idle switch. This is trivial to do on the ECU Config→RPM/TPS tab. You will also want to calibrate the TPS too.

References

The following files will be most useful to someone looking to confirm the information above or to find a new way to approach some of the issues.

EVO8 pin out
2G DSM pin out

EVO8 MFI schematic
2G MFI schematic

EVO8 cooling schematic
2G DSM cooling schematic