Not confident with automotive wiring? Have a professional harness builder or tuner do it, or check your work before first power-up. A wiring mistake can damage the ECU, the engine or the car, or start a fire.

100%

Stock ECU being replaced

SL4-B-3 EFI relay output (low side, 200 mA)

SL4-A-14 Auxiliary output 5

SL4-A-21 Digital input 2

SL4-A-10 Auxiliary output 1

SL4-A-15 Auxiliary output 6

SL4-A-22 Digital input 3

SL4-A-23 Digital input 4

SL4-A-20 Digital input 1

SL4-A-24 Digital input 5

SL4-A-16 Auxiliary output 7

OEM-1

Stock ECU being replaced

ACooling fan relay (low-side)

BA/C condenser fan relay

CStarter input (12V while cranking)

ECheck engine light (MIL)

GA/C clutch relay

KA/C pressure switch (A/C request)

LClutch switch

MVehicle speed sensor (VSS)

QBrake switch

UFuel pump relay (low-side)

SL4-B-11 Analog input 1

SL4-B-19 Analog input 6

SL4-B-20 Analog input 7 (switchable 1k pull-up)

SL4-B-12 Analog input 2

SL4-B-13 Analog input 3

SL4-B-14 Analog input 4

5V ref

SL4-B-22 Analog input 9 (switchable 1k pull-up)

SL4-B-21 Analog input 8 (switchable 1k pull-up)

SL4-A-25 Digital input 6

SL4-A-17 Auxiliary output 8

SL4-B-15 Analog input 5

0V sensor

SL4-B-23 Analog input 10 (switchable 1k pull-up)

OEM-3

Stock ECU being replaced

BMAF sensor input

CFront O2 sensor input

DRear O2 sensor input

FThrottle position (TPS)

GEngine coolant temp (CLT)

HEGR boost sensor

I+5V sensor reference

JEGR valve position sensor

KIntake air temp (IAT)

LIdle switch (closed throttle)

MFront O2 heater control

NEGR boost sensor (2nd channel)

OSensor ground

PPower steering pressure switch

GND

ECU power +12V (main relay)

GND

SL4-B-5 Crank index sensor +

SL4-B-7 Sync sensor +

0V sensor

SL4-A-11 Auxiliary output 2

GND

SL4-A-26 Ignition channel 1

SL4-A-12 Auxiliary output 3

SL4-A-13 Auxiliary output 4

SL4-A-27 Ignition channel 2

SL4-A-1 Injection channel 1

SL4-A-2 Injection channel 2

SL4-A-3 Injection channel 3

SL4-A-4 Injection channel 4

OEM-4

Stock ECU being replaced

AChassis ground

BECU power +12V (main relay)

CChassis ground

DChassis ground

ECrank position (CKP) sensor

GCAS SGC (cam sync)

HCrank pickup timing ground (CKP gnd)

JPRC solenoid (FPR control)

KChassis ground

NIgnition coil trigger (cyl 1&4)

OEGR vent solenoid

PEGR vacuum solenoid

RIgnition coil trigger (cyl 2&3)

UInjector 1 (cyl 1)

VInjector 2 (cyl 2)

WInjector 3 (cyl 3)

XInjector 4 (cyl 4)

SL4

SL4-A

SL4

1Injection channel 1

2Injection channel 2

3Injection channel 3

4Injection channel 4

5–8 no data

10Auxiliary output 1

11Auxiliary output 2

12Auxiliary output 3

13Auxiliary output 4

14Auxiliary output 5

15Auxiliary output 6

16Auxiliary output 7

17Auxiliary output 8

20Digital input 1

21Digital input 2

22Digital input 3

23Digital input 4

24Digital input 5

25Digital input 6

26Ignition channel 1

27Ignition channel 2

30–33 no data

34Aux 9–10 14V supply

OEM-4-U Injector 1 (cyl 1)

OEM-4-V Injector 2 (cyl 2)

OEM-4-W Injector 3 (cyl 3)

OEM-4-X Injector 4 (cyl 4)

5–8 no data

OEM-1-E Check engine light (MIL)

OEM-4-J PRC solenoid (FPR control)

OEM-4-O EGR vent solenoid

OEM-4-P EGR vacuum solenoid

OEM-1-B A/C condenser fan relay

OEM-1-G A/C clutch relay

OEM-1-U Fuel pump relay (low-side)

OEM-3-M Front O2 heater control

OEM-1-M Vehicle speed sensor (VSS)

OEM-1-C Starter input (12V while cranking)

OEM-1-K A/C pressure switch (A/C request)

OEM-1-L Clutch switch

OEM-1-Q Brake switch

OEM-3-L Idle switch (closed throttle)

OEM-4-N Ignition coil trigger (cyl 1&4)

OEM-4-R Ignition coil trigger (cyl 2&3)

30–33 no data

Aux 9–10 14V supply

SL4-B

SL4

1ECU 14V supply

2Sensor supply Vref1 5.0V

3EFI relay output (low side, 200 mA)

5Crank index sensor +

6Crank index sensor −

7Sync sensor +

8Sync sensor −

10Analog sensor 0V reference

11Analog input 1

12Analog input 2

13Analog input 3

14Analog input 4

15Analog input 5

18ECU ground

19Analog input 6

20Analog input 7 (switchable 1k pull-up)

21Analog input 8 (switchable 1k pull-up)

22Analog input 9 (switchable 1k pull-up)

23Analog input 10 (switchable 1k pull-up)

26ECU ground

29–30 no data

ECU 14V supply

5V ref

OEM-1-A Cooling fan relay (low-side)

OEM-4-E Crank position (CKP) sensor

SP-0V · 2 pins

OEM-4-G CAS SGC (cam sync)

SP-0V · 2 pins

0V sensor

OEM-3-B MAF sensor input

OEM-3-F Throttle position (TPS)

OEM-3-G Engine coolant temp (CLT)

OEM-3-H EGR boost sensor

OEM-3-N EGR boost sensor (2nd channel)

GND

OEM-3-C Front O2 sensor input

OEM-3-D Rear O2 sensor input

OEM-3-K Intake air temp (IAT)

OEM-3-J EGR valve position sensor

OEM-3-P Power steering pressure switch

GND

29–30 no data

SP-14V · 4 pins

SP-0V · 6 pins

SP-GND · 7 pins