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
T12-C3-9 Lambda 1 Heater Negative
T12-C3-4 PWM 9
ECM power (J271 relay feed)
0V sensor
T12-C2-5 Analogue 3
0V sensor
T12-C2-18 Analogue 5
0V sensor
T12-C3-28 PWM 10
T12-C3-24 PWM 6
T12-C3-25 PWM 7
T12-C3-7 Lambda 1 Pump Current
T12-C3-1 Lambda 2 Pump Current
T12-C2-10 Analogue 1
T12-C2-2 Wheel 1
T12-C3-34 CAN 2 Low
T12-C3-33 CAN 2 High
Battery constant +12V (term 30)
T12-C3-3 Lambda 2 Heater Negative
T12-C3-10 PWM 8
T12-C1-5 PWM 1
T12-C1-4 PWM 2
T12-C3-17 Analogue 7
T12-C3-18 Analogue 8
T12-C3-12 Lambda 1 Nernst Voltage
T12-C3-6 Lambda 2 Nernst Voltage
5V ref
5V ref
T12-C2-12 Crank
5V ref
T12-C2-6 Analogue 4
T12-C2-25 Thermistor 2
T12-C2-22 Cam 1
T12-C1-25 Injector 4
T12-C1-17 Injector 2
0V sensor
0V sensor
T12-C2-19 Analogue 6
T12-C2-7 Thermistor 1
T12-C1-26 Coil 4
T12-C1-18 Coil 2
T12-C1-9 Injector 1
T12-C1-34 Injector 3
5V ref
5V ref
T12-C2-1 Analogue 2
T12-C1-10 Coil 1
T12-C1-1 Coil 3
T12-C1-3 PWM 3
T12-C3-22 PWM 4
T12-C3-31 Knock 1
T12-C3-32 Knock 2
0V sensor
T12-C3-23 PWM 5
T12-C1-6 Motor 1 +
T12-C1-7 Motor 1 -
ECM + coil power (J271 relay feed)
OEM-T121
Stock ECU being replaced
1ECU ground
2ECU ground
5Wideband lambda heater (Z19)
9Secondary-air injection valve (N112)
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)
37Engine speed signal (tacho to cluster)
47Check engine light (MIL)
48EPC warning light
51Wideband lambda pump (G39)
52Wideband 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)
64EVAP canister valve (N80)
65Fuel pump relay control
66Secondary-air pump relay (J299)
68Post-cat lambda signal (G130)
69Post-cat lambda signal (G130)
70Wideband lambda Nernst signal (G39)
71Wideband 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)
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)
T12
T12-C1
T12
1Coil 3
3PWM 3
4PWM 2
5PWM 1
6Motor 1 +
7Motor 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-T121-104 Boost control solenoid (N75)
OEM-T121-66 Secondary-air pump relay (J299)
OEM-T121-65 Fuel pump relay control
OEM-T121-117 Throttle motor G186 (+)
OEM-T121-118 Throttle motor G186 (−)
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)
T12-C2
T12
1Analogue 2
2Wheel 1
5Analogue 3
6Analogue 4
7Thermistor 1
95v Output
10Analogue 1
12Crank
18Analogue 5
19Analogue 6
21Sensor Ground
22Cam 1
245v Output
25Thermistor 2
33Sensor Ground
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)
OEM-T121-92 Throttle position sensor 2 (G188)
0V sensor
OEM-T121-86 Camshaft position sensor (G40)
5V ref
OEM-T121-85 Intake air temperature (G42)
0V sensor
T12-C3
T12
1Lambda 2 Pump Current
3Lambda 2 Heater Negative
4PWM 9
6Lambda 2 Nernst Voltage
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
28PWM 10
31Knock 1
32Knock 2
33CAN 2 High
34CAN 2 Low
OEM-T121-52 Wideband lambda pump (G39)
OEM-T121-63 Post-cat lambda heater (Z29)
OEM-T121-9 Secondary-air injection valve (N112)
OEM-T121-71 Wideband lambda Nernst signal (G39)
OEM-T121-51 Wideband lambda pump (G39)
OEM-T121-5 Wideband lambda heater (Z19)
OEM-T121-64 EVAP canister valve (N80)
OEM-T121-70 Wideband lambda Nernst signal (G39)
OEM-T121-68 Post-cat lambda signal (G130)
OEM-T121-69 Post-cat lambda signal (G130)
OEM-T121-105 Diverter valve (N249)
OEM-T121-115 VVT camshaft adjustment valve (N205)
OEM-T121-47 Check engine light (MIL)
OEM-T121-48 EPC warning light
Permanent 12v
OEM-T121-37 Engine speed signal (tacho to cluster)
OEM-T121-106 Knock sensor 1 (G61)
OEM-T121-107 Knock sensor 2 (G66)
OEM-T121-60 CAN bus high
OEM-T121-58 CAN bus low
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.