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
MICROSQUIRT-A-8 FP (pump)
MICROSQUIRT-A-16 ALED
MICROSQUIRT-A-31 OPTO-
MICROSQUIRT-A-17 WLED
MICROSQUIRT-A-6 FLEX
MICROSQUIRT-A-30 OPTO+
MICROSQUIRT-A-7 FIDLE
OEM-1
Stock ECU being replaced
ACooling fan relay (low-side)
BA/C condenser fan relay
CStarter input (12V while cranking)
GA/C clutch relay
KA/C pressure switch (A/C request)
MVehicle speed sensor (VSS)
UFuel pump relay (low-side)
MICROSQUIRT-A-5 SPAREADC2 (MAF)
MICROSQUIRT-A-34 O2
MICROSQUIRT-A-27 TPS
MICROSQUIRT-A-25 CLT
MICROSQUIRT-A-24 MAP
5V ref
MICROSQUIRT-A-26 MAT
MICROSQUIRT-A-29 SPAREADC
0V sensor
OEM-3
Stock ECU being replaced
BMAF sensor input
CFront O2 sensor input
FThrottle position (TPS)
GEngine coolant temp (CLT)
HEGR boost sensor
I+5V sensor reference
KIntake air temp (IAT)
NEGR boost sensor (2nd channel)
OSensor ground
GND
ECU power +12V (main relay)
GND
GND
MICROSQUIRT-A-32 VR1+
MICROSQUIRT-A-21 VR2-
MICROSQUIRT-A-4 VR2+
0V sensor
GND
MICROSQUIRT-A-35 TACHO
MICROSQUIRT-A-11 SPK B (IGN2)
MICROSQUIRT-A-12 SPK A (IGN 1)
MICROSQUIRT-A-9 INJ 1
MICROSQUIRT-A-10 INJ 2
MICROSQUIRT-A-9 INJ 1
MICROSQUIRT-A-10 INJ 2
OEM-4
Stock ECU being replaced
AChassis ground
BECU power +12V (main relay)
CChassis ground
DChassis ground
ECrank position (CKP) sensor
FCAS SGT (cam trigger)
GCAS SGC (cam sync)
HCrank pickup timing ground (CKP gnd)
KChassis ground
LTachometer output
NIgnition coil trigger (cyl 1&4)
RIgnition coil trigger (cyl 2&3)
UInjector 1 (cyl 1)
VInjector 2 (cyl 2)
WInjector 3 (cyl 3)
XInjector 4 (cyl 4)
MICROSQUIRT
MICROSQUIRT-A
MICROSQUIRT
1+12V In
4VR2+
5SPAREADC2 (MAF)
6FLEX
7FIDLE
8FP (pump)
9INJ 1
10INJ 2
11SPK B (IGN2)
12SPK A (IGN 1)
16ALED
17WLED
18Sensor Ground
19Serial Ground
20Sensor Ground
21VR2-
22POWER GROUND
23POWER GROUND
24MAP
25CLT
26MAT
27TPS
28TPS VREF (5V)
29SPAREADC
30OPTO+
31OPTO-
32VR1+
34O2
35TACHO
+12V In
OEM-4-G CAS SGC (cam sync)
OEM-3-B MAF sensor input
OEM-1-K A/C pressure switch (A/C request)
OEM-1-U Fuel pump relay (low-side)
OEM-1-A Cooling fan relay (low-side)
Injector 3 (cyl 3) · 2 pins
Injector 4 (cyl 4) · 2 pins
OEM-4-N Ignition coil trigger (cyl 1&4)
OEM-4-R Ignition coil trigger (cyl 2&3)
OEM-1-B A/C condenser fan relay
OEM-1-G A/C clutch relay
0V sensor
0V sensor
0V sensor
OEM-4-F CAS SGT (cam trigger)
GND
GND
OEM-3-H EGR boost sensor
OEM-3-G Engine coolant temp (CLT)
OEM-3-K Intake air temp (IAT)
OEM-3-F Throttle position (TPS)
5V ref
OEM-3-N EGR boost sensor (2nd channel)
OEM-1-M Vehicle speed sensor (VSS)
OEM-1-C Starter input (12V while cranking)
OEM-4-E Crank position (CKP) sensor
OEM-3-C Front O2 sensor input
OEM-4-L Tachometer output
SP-14V · 3 pins
SP-0V · 6 pins
SP-GND · 7 pins
Press enter or space to select a node. You can then use the arrow keys to move the node around. Press delete to remove it and escape to cancel.
Press enter or space to select an edge. You can then press delete to remove it or escape to cancel.