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
GND
GND
MS3PROMINI-A-6 Injector out B
ECM power (J271 relay feed)
0V sensor
MS3PROMINI-A-28 TPS in
0V sensor
MS3PROMINI-A-16 Analog in 4
0V sensor
MS3PROMINI-A-13 Analog in 1
MS3PROMINI-A-34 Digital frequency in 1 (Hall)
MS3PROMINI-A-24 CAN Low
MS3PROMINI-A-25 CAN High
MS3PROMINI-A-7 Injector out C
MS3PROMINI-A-4 Fuel pump out
MS3PROMINI-A-3 PWM out 1 / Idle
5V ref
5V ref
MS3PROMINI-A-30 CKP+
5V ref
MS3PROMINI-A-15 Analog in 3
MS3PROMINI-A-27 IAT in
MS3PROMINI-A-32 CMP+
MS3PROMINI-A-5 Injector out A
MS3PROMINI-A-11 Injector out G
0V sensor
0V sensor
MS3PROMINI-A-26 CLT in
MS3PROMINI-A-20 Spark out D
MS3PROMINI-A-18 Spark out B
MS3PROMINI-A-10 Injector out F
MS3PROMINI-A-12 Injector out H
5V ref
5V ref
MS3PROMINI-A-14 Analog in 2
MS3PROMINI-A-17 Spark out A
MS3PROMINI-A-19 Spark out C
MS3PROMINI-A-8 Injector out D
MS3PROMINI-A-9 Injector out E
0V sensor
ECM + coil power (J271 relay feed)
OEM-T121
Stock ECU being replaced
1ECU ground
2ECU ground
5Wideband lambda heater (Z19)
21ECM power (J271 relay feed)
29MAF sensor ground (G70)
33Accelerator pedal position 1 (G79)
34Accelerator pedal position 1 ground (G79)
35Accelerator pedal position 2 (G185)
36Accelerator pedal position 2 ground (G185)
53MAF sensor signal (G70)
54Road speed signal (VSS)
58CAN bus low
60CAN bus high
63Post-cat lambda heater (Z29)
65Fuel pump relay control
66Secondary-air pump relay (J299)
72Accelerator pedal position 1 5V supply (G79)
73Accelerator pedal position 2 5V supply (G185)
82Crank position sensor (G28)
83Throttle position sensor 5V supply (G187/G188)
84Throttle position sensor 1 (G187)
85Intake air temperature (G42)
86Camshaft position sensor (G40)
88Injector 4 (N33)
89Injector 2 (N31)
90Crank position sensor ground (G28)
91Throttle position sensor ground (G187/G188)
93Engine coolant temperature (G62)
94Ignition coil 4 (N163)
95Ignition coil 2 (N128)
96Injector 1 (N30)
97Injector 3 (N32)
98Cam + boost sensor 5V supply (G40/G31)
99Knock sensor 5V supply (G61/G66)
101Boost pressure sensor (G31)
102Ignition coil 1 (N127)
103Ignition coil 3 (N158)
104Boost control solenoid (N75)
105Diverter valve (N249)
108Sensor ground
121ECM + coil power (J271 relay feed)
MS3PROMINI
MS3PROMINI-A
MS3PROMINI
112V+ switched power in
2+5V VREF out
3PWM out 1 / Idle
4Fuel pump out
5Injector out A
6Injector out B
7Injector out C
8Injector out D
9Injector out E
10Injector out F
11Injector out G
12Injector out H
13Analog in 1
14Analog in 2
15Analog in 3
16Analog in 4
17Spark out A
18Spark out B
19Spark out C
20Spark out D
21Sensor ground
22Power ground
23Power ground
24CAN Low
25CAN High
26CLT in
27IAT in
28TPS in
30CKP+
32CMP+
34Digital frequency in 1 (Hall)
12V+ switched power in
5V ref
OEM-T121-66 Secondary-air pump relay (J299)
OEM-T121-65 Fuel pump relay control
OEM-T121-88 Injector 4 (N33)
OEM-T121-5 Wideband lambda heater (Z19)
OEM-T121-63 Post-cat lambda heater (Z29)
OEM-T121-104 Boost control solenoid (N75)
OEM-T121-105 Diverter valve (N249)
OEM-T121-96 Injector 1 (N30)
OEM-T121-89 Injector 2 (N31)
OEM-T121-97 Injector 3 (N32)
OEM-T121-53 MAF sensor signal (G70)
OEM-T121-101 Boost pressure sensor (G31)
OEM-T121-84 Throttle position sensor 1 (G187)
OEM-T121-35 Accelerator pedal position 2 (G185)
OEM-T121-102 Ignition coil 1 (N127)
OEM-T121-95 Ignition coil 2 (N128)
OEM-T121-103 Ignition coil 3 (N158)
OEM-T121-94 Ignition coil 4 (N163)
0V sensor
GND
GND
OEM-T121-58 CAN bus low
OEM-T121-60 CAN bus high
OEM-T121-93 Engine coolant temperature (G62)
OEM-T121-85 Intake air temperature (G42)
OEM-T121-33 Accelerator pedal position 1 (G79)
OEM-T121-82 Crank position sensor (G28)
OEM-T121-86 Camshaft position sensor (G40)
OEM-T121-54 Road speed signal (VSS)
SP-GND · 5 pins
SP-14V · 4 pins
SP-0V · 8 pins
SP-5V1 · 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.