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
MS3PROEVOHC-B-19 Digital switched 12V in
MS3PROEVOHC-C-4 Digital out 1
MS3PROEVOHC-B-2 Injector out B
ECM power (J271 relay feed)
MS3PROEVOHC-A-2 High current out 2
MS3PROEVOHC-C-3 Digital out 2
MS3PROEVOHC-A-32 Digital switched in 1
0V sensor
MS3PROEVOHC-A-9 TPS in
0V sensor
MS3PROEVOHC-A-22 Analog In 4
0V sensor
MS3PROEVOHC-A-24 Tach out
MS3PROEVOHC-B-20 Digital switched in 2
MS3PROEVOHC-B-29 Digital switched in 3
MS3PROEVOHC-C-11 Digital switched in 4
MS3PROEVOHC-C-10 Digital switched in 5
MS3PROEVOHC-A-5 High current out 3
MS3PROEVOHC-B-11 Injector out G
MS3PROEVOHC-B-34 Digital Frequency in 1 (VR+)
MS3PROEVOHC-A-19 Analog in 1
MS3PROEVOHC-B-28 Digital frequency in 1 (unconditioned)
MS3PROEVOHC-B-35 Digital Frequency in 1 (VR−)
MS3PROEVOHC-B-17 Digital frequency in 2 (Hall)
MS3PROEVOHC-B-21 Digital frequency in 3 (unconditioned)
MS3PROEVOHC-A-33 CAN L
MS3PROEVOHC-A-34 CAN H
MS3PROEVOHC-A-29 PWM out 2
MS3PROEVOHC-B-12 Injector out H
MS3PROEVOHC-A-28 Fuel pump relay out
MS3PROEVOHC-A-14 PWM / Idle Out 1
MS3PROEVOHC-B-22 Digital Frequency in 3 (VR+)
MS3PROEVOHC-A-25 O2 in
MS3PROEVOHC-A-12 Analog In 6
5V ref
5V ref
MS3PROEVOHC-B-23 Digital Frequency In 3 (VR−)
MS3PROEVOHC-A-17 Analog In 7
MS3PROEVOHC-A-30 PWM out 3
MS3PROEVOHC-A-6 CKP+
5V ref
MS3PROEVOHC-A-21 Analog in 3
MS3PROEVOHC-A-10 MAT in
MS3PROEVOHC-A-26 CMP+
MS3PROEVOHC-B-10 Injector out F
MS3PROEVOHC-A-4 Injector out I
0V sensor
0V sensor
MS3PROEVOHC-A-23 Analog In 5
MS3PROEVOHC-A-11 CLT in
MS3PROEVOHC-B-16 Spark out H
MS3PROEVOHC-B-14 Spark out E
MS3PROEVOHC-A-3 Injector out J
MS3PROEVOHC-B-1 Injector out A
5V ref
5V ref
MS3PROEVOHC-A-20 Analog in 2
MS3PROEVOHC-B-13 Spark out G
MS3PROEVOHC-B-15 Spark out C
MS3PROEVOHC-C-2 PWM out 4
MS3PROEVOHC-C-1 PWM out 5
MS3PROEVOHC-A-31 Knock in 1
MS3PROEVOHC-A-7 Knock In 2
0V sensor
MS3PROEVOHC-A-1 High current out 1
MS3PROEVOHC-B-30 Stepper IAC out 1B
MS3PROEVOHC-B-31 Stepper IAC out 1A
ECM + coil power (J271 relay feed)
OEM-T121
Stock ECU being replaced
1ECU ground
2ECU ground
3Ignition switch +12V (term 15)
5Wideband lambda heater (Z19)
9Secondary-air injection valve (N112)
21ECM power (J271 relay feed)
22Brake vacuum pump (V192)
25V144 Evaporative diagnostic pump (Pin 2)
28Alternator DF terminal (charge warning)
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)
37Engine speed signal (tacho to cluster)
38Cruise control switch (E45)
39Clutch pedal switch (F36)
40A/C signal
41A/C signal
47Check engine light (MIL)
48EPC warning light
49Power steering pressure switch (F88)
53MAF sensor signal (G70)
54Road speed signal (VSS)
55Brake pedal switch (F)
56Brake pedal switch (F)
57Cruise control switch (E45)
58CAN bus low
60CAN bus high
63Post-cat lambda heater (Z29)
64EVAP canister valve (N80)
65Fuel pump relay control
66Secondary-air pump relay (J299)
67Crash sensor signal
68Post-cat lambda signal (G130)
69Post-cat lambda signal (G130)
72Accelerator pedal position 1 5V supply (G79)
73Accelerator pedal position 2 5V supply (G185)
75Cruise control switch (E45)
76Cruise control switch (E45)
80V144 Evap Diagnostic Pump (Pin 1)
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)
92Throttle position sensor 2 (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)
106Knock sensor 1 (G61)
107Knock sensor 2 (G66)
108Sensor ground
115VVT camshaft adjustment valve (N205)
117Throttle motor G186 (+)
118Throttle motor G186 (−)
121ECM + coil power (J271 relay feed)
MS3PROEVOHC
MS3PROEVOHC-A
MS3PROEVOHC
1High current out 1
2High current out 2
3Injector out J
4Injector out I
5High current out 3
6CKP+
7Knock In 2
85V+ VREF out
9TPS in
10MAT in
11CLT in
12Analog In 6
13Logic Ground
14PWM / Idle Out 1
15CKP−
17Analog In 7
18Sensor return
19Analog in 1
20Analog in 2
21Analog in 3
22Analog In 4
23Analog In 5
24Tach out
25O2 in
26CMP+
27CMP−
28Fuel pump relay out
29PWM out 2
30PWM out 3
31Knock in 1
32Digital switched in 1
33CAN L
34CAN H
3512V+ switched power in
OEM-T121-115 VVT camshaft adjustment valve (N205)
OEM-T121-22 Brake vacuum pump (V192)
OEM-T121-96 Injector 1 (N30)
OEM-T121-89 Injector 2 (N31)
OEM-T121-47 Check engine light (MIL)
OEM-T121-82 Crank position sensor (G28)
OEM-T121-107 Knock sensor 2 (G66)
5V ref
OEM-T121-33 Accelerator pedal position 1 (G79)
OEM-T121-85 Intake air temperature (G42)
OEM-T121-93 Engine coolant temperature (G62)
OEM-T121-69 Post-cat lambda signal (G130)
0V sensor
OEM-T121-66 Secondary-air pump relay (J299)
SP-0V · 6 pins
OEM-T121-76 Cruise control switch (E45)
0V sensor
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-T121-92 Throttle position sensor 2 (G188)
OEM-T121-37 Engine speed signal (tacho to cluster)
OEM-T121-68 Post-cat lambda signal (G130)
OEM-T121-86 Camshaft position sensor (G40)
SP-0V · 6 pins
OEM-T121-65 Fuel pump relay control
OEM-T121-63 Post-cat lambda heater (Z29)
OEM-T121-80 V144 Evap Diagnostic Pump (Pin 1)
OEM-T121-106 Knock sensor 1 (G61)
OEM-T121-28 Alternator DF terminal (charge warning)
OEM-T121-58 CAN bus low
OEM-T121-60 CAN bus high
12V+ switched power in
MS3PROEVOHC-B
MS3PROEVOHC
1Injector out A
2Injector out B
3Ground
5Ground
7Ground
9Ground
10Injector out F
11Injector out G
12Injector out H
13Spark out G
14Spark out E
15Spark out C
16Spark out H
17Digital frequency in 2 (Hall)
19Digital switched 12V in
20Digital switched in 2
21Digital frequency in 3 (unconditioned)
22Digital Frequency in 3 (VR+)
23Digital Frequency In 3 (VR−)
28Digital frequency in 1 (unconditioned)
29Digital switched in 3
30Stepper IAC out 1B
31Stepper IAC out 1A
34Digital Frequency in 1 (VR+)
35Digital Frequency in 1 (VR−)
OEM-T121-97 Injector 3 (N32)
OEM-T121-9 Secondary-air injection valve (N112)
GND
GND
GND
GND
OEM-T121-88 Injector 4 (N33)
OEM-T121-48 EPC warning light
OEM-T121-64 EVAP canister valve (N80)
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)
OEM-T121-56 Brake pedal switch (F)
OEM-T121-3 Ignition switch +12V (term 15)
OEM-T121-38 Cruise control switch (E45)
OEM-T121-57 Cruise control switch (E45)
OEM-T121-67 Crash sensor signal
OEM-T121-75 Cruise control switch (E45)
OEM-T121-54 Road speed signal (VSS)
OEM-T121-39 Clutch pedal switch (F36)
OEM-T121-117 Throttle motor G186 (+)
OEM-T121-118 Throttle motor G186 (−)
OEM-T121-49 Power steering pressure switch (F88)
OEM-T121-55 Brake pedal switch (F)
MS3PROEVOHC-C
MS3PROEVOHC
1PWM out 5
2PWM out 4
3Digital out 2
4Digital out 1
10Digital switched in 5
11Digital switched in 4
155V+ VREF out 2
17Sensor return
18Sensor return
19Sensor return
20Sensor return
21Sensor return
225V+ VREF out 1
OEM-T121-105 Diverter valve (N249)
OEM-T121-104 Boost control solenoid (N75)
OEM-T121-25 V144 Evaporative diagnostic pump (Pin 2)
OEM-T121-5 Wideband lambda heater (Z19)
OEM-T121-41 A/C signal
OEM-T121-40 A/C signal
5V ref
0V sensor
0V sensor
0V sensor
0V sensor
0V sensor
5V ref
SP-GND · 7 pins
SP-5V1 · 4 pins
SP-14V · 4 pins
SP-0V · 16 pins
SP-5V2 · 4 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.