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.
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Stock ECU being replaced
GND
GND
T4-C3-9 Lambda 1 Heater Negative
ECM power (J271 relay feed)
0V sensor
T4-C2-5 Analogue 3
0V sensor
T4-C2-19 Analogue 6
0V sensor
T4-C3-25 PWM 7
T4-C3-10 PWM 8
T4-C3-7 Lambda 1 Pump Current
T4-C2-10 Analogue 1
T4-C2-2 Wheel 1
T4-C2-28 CAN Low
T4-C2-26 CAN High
Battery constant +12V (term 30)
T4-C1-3 PWM 3
T4-C1-5 PWM 1
T4-C1-4 PWM 2
T4-C3-18 Analogue 8
T4-C2-34 Analogue 9
T4-C3-12 Lambda 1 Nernst Voltage
5V ref
5V ref
T4-C2-12 Crank
5V ref
T4-C2-6 Analogue 4
T4-C2-25 Thermistor 2
T4-C2-22 Cam 1
T4-C1-25 Injector 4
T4-C1-17 Injector 2
0V sensor
0V sensor
T4-C3-17 Analogue 7
T4-C2-7 Thermistor 1
T4-C1-26 Coil 4
T4-C1-18 Coil 2
T4-C1-9 Injector 1
T4-C1-34 Injector 3
5V ref
5V ref
T4-C2-1 Analogue 2
T4-C1-10 Coil 1
T4-C1-1 Coil 3
T4-C3-22 PWM 4
T4-C3-23 PWM 5
0V sensor
T4-C3-24 PWM 6
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)
47Check engine light (MIL)
48EPC warning light
51Wideband lambda pump (G39)
53MAF sensor signal (G70)
54Road speed signal (VSS)
58CAN bus low
60CAN bus high
62Battery constant +12V (term 30)
63Post-cat lambda heater (Z29)
65Fuel pump relay control
66Secondary-air pump relay (J299)
68Post-cat lambda signal (G130)
69Post-cat lambda signal (G130)
70Wideband lambda Nernst signal (G39)
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)
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)
108Sensor ground
115VVT camshaft adjustment valve (N205)
121ECM + coil power (J271 relay feed)
T4
T4-C1
T4
1Coil 3
3PWM 3
4PWM 2
5PWM 1
9Injector 1
10Coil 1
13Power Ground 1
14Power Ground 2
17Injector 2
18Coil 2
25Injector 4
26Coil 4
31Ignition 12v In
34Injector 3
OEM-T121-103 Ignition coil 3 (N158)
OEM-T121-63 Post-cat lambda heater (Z29)
OEM-T121-66 Secondary-air pump relay (J299)
OEM-T121-65 Fuel pump relay control
OEM-T121-96 Injector 1 (N30)
OEM-T121-102 Ignition coil 1 (N127)
GND
GND
OEM-T121-89 Injector 2 (N31)
OEM-T121-95 Ignition coil 2 (N128)
OEM-T121-88 Injector 4 (N33)
OEM-T121-94 Ignition coil 4 (N163)
Ignition 12v In
OEM-T121-97 Injector 3 (N32)
T4-C2
T4
1Analogue 2
2Wheel 1
5Analogue 3
6Analogue 4
7Thermistor 1
95v Output
10Analogue 1
12Crank
19Analogue 6
21Sensor Ground
22Cam 1
245v Output
25Thermistor 2
26CAN High
28CAN Low
33Sensor Ground
34Analogue 9
OEM-T121-101 Boost pressure sensor (G31)
OEM-T121-54 Road speed signal (VSS)
OEM-T121-33 Accelerator pedal position 1 (G79)
OEM-T121-84 Throttle position sensor 1 (G187)
OEM-T121-93 Engine coolant temperature (G62)
5V ref
OEM-T121-53 MAF sensor signal (G70)
OEM-T121-82 Crank position sensor (G28)
OEM-T121-35 Accelerator pedal position 2 (G185)
0V sensor
OEM-T121-86 Camshaft position sensor (G40)
5V ref
OEM-T121-85 Intake air temperature (G42)
OEM-T121-60 CAN bus high
OEM-T121-58 CAN bus low
0V sensor
OEM-T121-69 Post-cat lambda signal (G130)
T4-C3
T4
7Lambda 1 Pump Current
9Lambda 1 Heater Negative
10PWM 8
12Lambda 1 Nernst Voltage
17Analogue 7
18Analogue 8
22PWM 4
23PWM 5
24PWM 6
25PWM 7
26Permanent 12v
OEM-T121-51 Wideband lambda pump (G39)
OEM-T121-5 Wideband lambda heater (Z19)
OEM-T121-48 EPC warning light
OEM-T121-70 Wideband lambda Nernst signal (G39)
OEM-T121-92 Throttle position sensor 2 (G188)
OEM-T121-68 Post-cat lambda signal (G130)
OEM-T121-104 Boost control solenoid (N75)
OEM-T121-105 Diverter valve (N249)
OEM-T121-115 VVT camshaft adjustment valve (N205)
OEM-T121-47 Check engine light (MIL)
Permanent 12v
SP-GND · 5 pins
SP-14V · 4 pins
SP-0V · 9 pins
SP-5V2 · 5 pins
SP-5V1 · 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.