FAQ: SM2, SMC & SMC FAMILY PLUG-IN ECU INJECTOR COMPATIBILITY
CHANGING THE ECU INJECTOR DRIVE CURRENT |
ECU |
Jumpering for low Current (2/0.5 Amp peak/hold) |
Jumpering for High Current (4/1 Amp peak/hold) |
|
SMC (rev A, B & C PCBs to S/N: L5386) |
Non-configurable injector drivers ICs ¹ |
|
SM2 (rev A, B, C, D & E PBCs to S/N: L2025) |
Non-configurable injector drivers ICs ¹ |
|
Plug-in ECUs for Mitsubishi EVO IV to VIII & Subaru WRX-STI 1999 - 2000 (rev A & B PCBs B/N 1350-01 A & B) |
Non-configurable injector drivers ICs ¹ |
|
SMC (rev D & E PCBs from S/N: L5387) |
JP2 link pins 1-2 |
JP2 link pins 2-3 |
See Jumper location |
SM2 (rev F & G PBCs from S/N: L2026) |
CON3 link pins 1-2 |
CON3 link pins 2-3 |
See Jumper location |
Plug-in ECUs for Mitsubishi EVO IV to VIII & Subaru WRX-STI 1999 - 2000 (rev C & D PCBs B/N 1350-01 C & D) |
JP2 link pins 1-2 |
JP2 open circuit pins 1-2 |
See Jumper location |
Notes:-
¹ ECUs equipped with non-configurable driver ICs can only have their drive current changed by replacing the driver ICs. The AUTRONIC service centre has limited quantities of these now obsolete drivers. We can provide a service to change drivers to suit your injectors, subject to driver availability.
Accurate delivery of fuel requires both correct electrical drive and precise compensation for the electro-mechanical properties of the injector (dead time correction). Correct injector operation, avoidance of injector and/or engine damage requires that both the dead time calibration and the driver characteristic match the engine's injectors.
The SMC, SMC Marine, Mitsubishi EVO IV to VIII, Subaru WRX-STI 1999-2000 and SM2 ECUs do not have programmable injector output current drive selection. Therefore the PC software injector calibration screen is only able to perform injector dead time correction selection. The actual injector drive current characteristic is determined by the installed driver type and/or an internal PCB jumper selection.
The OEM installation in some vehicles (e.g. Mitsubishi EVO) will have ballast resistors connected in series with the injectors. When fitting non OEM injectors these resistors may need to be removed. Refer to the PC software injector characteristic selection screen for ballast resistor requirements relevant to the injector type. If the injector selection list does not include a setting with ballast resistor, remove the resistors.
When making the injector type selection using the PC software, ensure that the ECU's output current drive characteristic matches the software recommended drive requirement.
IDENTIFYING THE ECU INJECTOR DRIVE CURRENT CHARACTERISTIC
SMC & SM2 ECU serial number coding allows identification of injector drive characteristic. ECUs with serial numbers ending in 'A2' provide 2/0.5 Amp peak and hold drive. Serial numbers ending with 'A4' deliver 4/1 Amp peak and hold drive. Early revision ECUs are equipped with fixed current injector driver ICs that are attached to the ECU's case. All later revision PCBs have configurable injector driver modules. See the table below for details.
Injector drive characteristics of the plug-in ECUs (Mitsubishi EVO IV to VIII & Subaru WRX/STI 1999 - 2000) cannot be determined from serial number coding. These ECUs usually are shipped with driver characteristics to match the OEM injectors of the intended vehicle model (usually 2/0.5 Amp). Early revision ECUs have fixed current injector driver ICs that are attached to an aluminium heat sink. Low current driver ICs (2/0.5 Amp) are inscribed with part numbers MC3484S2-1 or CS452, whereas high current driver ICs (4/1 Amp) have part numbers MC3484S4-2 or CS453. All later revision PCBs have configurable injector driver modules. See the table below for details.