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
M800-A-23 AUX3
M800-A-29 INJ7
ECM power (J271 relay feed)
0V sensor
M800-A-16 Analog Voltage Input 3
0V sensor
M800-A-25 Analog Voltage Input 5
0V sensor
M800-A-34 AUX8
M800-A-27 INJ5
M800-B-26 Lambda1 Pump Current
M800-B-13 Lambda2 Pump Current
M800-A-14 AV1
M800-B-8 Digital Input 1
M800-B-24 CAN Bus Low
M800-B-23 CAN Bus High
M800-A-24 AUX4
M800-A-28 INJ6
M800-A-18 AUX1
M800-A-1 AUX2
M800-B-21 AV7
M800-B-22 AV8
M800-B-25 Lambda1 Sense Voltage
M800-B-12 Lambda2 Sense Voltage
5V ref
5V ref
M800-B-1 Crank Reference Timing Input
5V ref
M800-A-17 Analog Voltage Input 4
M800-B-4 Analog Temperature Input 2
M800-B-2 Cam Sync Timing Input
M800-A-22 INJ4
M800-A-20 INJ2
0V sensor
0V sensor
M800-B-20 Analog Voltage Input 6
M800-B-3 Analog Temperature Input 1
M800-A-6 IGN4
M800-A-4 IGN2
M800-A-19 INJ1
M800-A-21 INJ3
5V ref
5V ref
M800-A-15 Analog Voltage Input 2
M800-A-3 IGN1
M800-A-5 IGN3
M800-A-31 AUX5
M800-A-32 AUX6
0V sensor
M800-A-33 AUX7
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)
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
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)
108Sensor ground
115VVT camshaft adjustment valve (N205)
121ECM + coil power (J271 relay feed)
M800
M800-A
M800
1AUX2
25V Engine Sensor Supply
3IGN1
4IGN2
5IGN3
6IGN4
95V Auxiliary Sensor Supply
10GND Battery Negative
11GND Battery Negative
14AV1
15Analog Voltage Input 2
16Analog Voltage Input 3
17Analog Voltage Input 4
18AUX1
19INJ1
20INJ2
21INJ3
22INJ4
23AUX3
24AUX4
25Analog Voltage Input 5
26VBAT Battery Positive
27INJ5
28INJ6
29INJ7
31AUX5
32AUX6
33AUX7
34AUX8
OEM-T121-66 Secondary-air pump relay (J299)
5V ref
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)
5V ref
GND
GND
OEM-T121-53 MAF sensor signal (G70)
OEM-T121-101 Boost pressure sensor (G31)
OEM-T121-33 Accelerator pedal position 1 (G79)
OEM-T121-84 Throttle position sensor 1 (G187)
OEM-T121-65 Fuel pump relay control
OEM-T121-96 Injector 1 (N30)
OEM-T121-89 Injector 2 (N31)
OEM-T121-97 Injector 3 (N32)
OEM-T121-88 Injector 4 (N33)
OEM-T121-5 Wideband lambda heater (Z19)
OEM-T121-63 Post-cat lambda heater (Z29)
OEM-T121-35 Accelerator pedal position 2 (G185)
VBAT Battery Positive
OEM-T121-48 EPC warning light
OEM-T121-64 EVAP canister valve (N80)
OEM-T121-9 Secondary-air injection valve (N112)
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)
M800-B
M800
1Crank Reference Timing Input
2Cam Sync Timing Input
3Analog Temperature Input 1
4Analog Temperature Input 2
8Digital Input 1
12Lambda2 Sense Voltage
13Lambda2 Pump Current
140V Comms Reference
150V Auxiliary Sensor Supply
160V Engine Sensor Supply
20Analog Voltage Input 6
21AV7
22AV8
23CAN Bus High
24CAN Bus Low
25Lambda1 Sense Voltage
26Lambda1 Pump Current
OEM-T121-82 Crank position sensor (G28)
OEM-T121-86 Camshaft position sensor (G40)
OEM-T121-93 Engine coolant temperature (G62)
OEM-T121-85 Intake air temperature (G42)
OEM-T121-54 Road speed signal (VSS)
OEM-T121-71 Wideband lambda Nernst signal (G39)
OEM-T121-52 Wideband lambda pump (G39)
0V sensor
0V sensor
0V sensor
OEM-T121-92 Throttle position sensor 2 (G188)
OEM-T121-68 Post-cat lambda signal (G130)
OEM-T121-69 Post-cat lambda signal (G130)
OEM-T121-60 CAN bus high
OEM-T121-58 CAN bus low
OEM-T121-70 Wideband lambda Nernst signal (G39)
OEM-T121-51 Wideband lambda pump (G39)
SP-GND · 5 pins
SP-5V1 · 5 pins
SP-5V2 · 4 pins
SP-14V · 4 pins
SP-0V · 10 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.