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
MAIN-R-COIL+ Relay coil positive (ignition-switched +12V)
M190-A-1 Low Side Injector 3
M190-A-32 Low Side Injector 10
ECM power (J271 relay feed)
M190-B-T Low Side Injector 6
M190-A-5 Low Side Injector 4
M190-A-21 Digital Input 1
0V sensor
M190-C-35 Analogue Voltage Input 3
0V sensor
M190-C-29 Analogue Voltage Input 5
0V sensor
M190-A-14 Digital Input 2
M190-A-30 Digital Input 3
M190-A-37 Digital Input 4
M190-C-27 Universal Digital Input 4
M190-A-25 Low Side Injector 7
M190-A-10 Low Side Injector 8
M190-C-40 Universal Digital Input 5
M190-C-42 Analogue Voltage Input 1
M190-C-25 Universal Digital Input 3
M190-C-47 Universal Digital Input 6
M190-C-17 Universal Digital Input 7
M190-C-10 Universal Digital Input 8
M190-C-31 CAN Bus 1 Low
M190-C-24 CAN Bus 1 High
Battery constant +12V (term 30)
M190-B-b Low Side Injector 3
M190-A-47 Low Side Injector 9
M190-A-2 Low Side Injector 2
M190-B-V Low Side Injector 2
M190-C-22 Universal Digital Input 9
M190-A-7 Lambda Narrow Input 1
M190-A-6 Lambda Narrow Input 2
5V ref
5V ref
M190-C-21 Universal Digital Input 10
M190-C-20 Universal Digital Input 11
M190-B-S Low Side Injector 4
M190-C-18 Universal Digital Input 1
5V ref
M190-C-28 Analogue Voltage Input 4
M190-C-39 Analogue Temperature Input 2
M190-C-32 Universal Digital Input 2
M190-A-12 Peak Hold Injector 2
M190-A-3 Low Side Injector 1
0V sensor
0V sensor
M190-C-11 Analogue Voltage Input 6
M190-C-37 Analogue Temperature Input 1
M190-C-1 Low Side Ignition 4
M190-C-8 Low Side Ignition 2
M190-A-11 Peak Hold Injector 1
M190-B-U Low Side Injector 1
5V ref
5V ref
M190-C-36 Analogue Voltage Input 2
M190-C-16 Low Side Ignition 1
M190-C-2 Low Side Ignition 3
M190-A-48 Low Side Injector 5
M190-B-a Low Side Injector 5
M190-C-51 Knock Input 1
M190-C-44 Knock Input 2
0V sensor
M190-A-40 Low Side Injector 6
M190-B-A Half Bridge Output 1
M190-B-B Half Bridge Output 2
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)
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
62Battery constant +12V (term 30)
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)
M190
M190-A
M190
1Low Side Injector 3
2Low Side Injector 2
3Low Side Injector 1
5Low Side Injector 4
6Lambda Narrow Input 2
7Lambda Narrow Input 1
8Sensor 5.0V C1
9Sensor 5.0V C2
10Low Side Injector 8
11Peak Hold Injector 1
12Peak Hold Injector 2
14Digital Input 2
16Sensor 5.0V C3
18Sensor 0V C1
19Sensor 0V C2
20Sensor 0V C3
21Digital Input 1
25Low Side Injector 7
30Digital Input 3
32Low Side Injector 10
37Digital Input 4
38Battery Backup
40Low Side Injector 6
47Low Side Injector 9
48Low Side Injector 5
OEM-T121-5 Wideband lambda heater (Z19)
OEM-T121-65 Fuel pump relay control
OEM-T121-89 Injector 2 (N31)
OEM-T121-25 V144 Evaporative diagnostic pump (Pin 2)
OEM-T121-69 Post-cat lambda signal (G130)
OEM-T121-68 Post-cat lambda signal (G130)
5V ref
5V ref
OEM-T121-48 EPC warning light
OEM-T121-96 Injector 1 (N30)
OEM-T121-88 Injector 4 (N33)
OEM-T121-38 Cruise control switch (E45)
5V ref
0V sensor
0V sensor
0V sensor
OEM-T121-28 Alternator DF terminal (charge warning)
OEM-T121-47 Check engine light (MIL)
OEM-T121-39 Clutch pedal switch (F36)
OEM-T121-9 Secondary-air injection valve (N112)
OEM-T121-40 A/C signal
Battery Backup
OEM-T121-115 VVT camshaft adjustment valve (N205)
OEM-T121-64 EVAP canister valve (N80)
OEM-T121-104 Boost control solenoid (N75)
M190-B
M190
aLow Side Injector 5
AHalf Bridge Output 1
bLow Side Injector 3
BHalf Bridge Output 2
cBattery Negative 6
GBattery Negative 1
HBattery Positive 1
JBattery Positive 2
KBattery Positive 3
LBattery Positive 4
SLow Side Injector 4
TLow Side Injector 6
ULow Side Injector 1
VLow Side Injector 2
WBattery Negative 2
XBattery Negative 3
YBattery Negative 4
ZBattery Negative 5
OEM-T121-105 Diverter valve (N249)
OEM-T121-117 Throttle motor G186 (+)
OEM-T121-63 Post-cat lambda heater (Z29)
OEM-T121-118 Throttle motor G186 (−)
GND
GND
Battery Positive 1
Battery Positive 2
Battery Positive 3
Battery Positive 4
OEM-T121-80 V144 Evap Diagnostic Pump (Pin 1)
OEM-T121-22 Brake vacuum pump (V192)
OEM-T121-97 Injector 3 (N32)
OEM-T121-66 Secondary-air pump relay (J299)
GND
GND
GND
GND
M190-C
M190
1Low Side Ignition 4
2Low Side Ignition 3
8Low Side Ignition 2
10Universal Digital Input 8
11Analogue Voltage Input 6
14Sensor 0V A1
15Sensor 0V A2
16Low Side Ignition 1
17Universal Digital Input 7
18Universal Digital Input 1
20Universal Digital Input 11
21Universal Digital Input 10
22Universal Digital Input 9
23Sensor 0V B1
24CAN Bus 1 High
25Universal Digital Input 3
27Universal Digital Input 4
28Analogue Voltage Input 4
29Analogue Voltage Input 5
30Sensor 0V B2
31CAN Bus 1 Low
32Universal Digital Input 2
35Analogue Voltage Input 3
36Analogue Voltage Input 2
37Analogue Temperature Input 1
39Analogue Temperature Input 2
40Universal Digital Input 5
42Analogue Voltage Input 1
44Knock Input 2
47Universal Digital Input 6
48Sensor 5.0V A1
50Sensor 5.0V B1
51Knock Input 1
OEM-T121-94 Ignition coil 4 (N163)
OEM-T121-103 Ignition coil 3 (N158)
OEM-T121-95 Ignition coil 2 (N128)
OEM-T121-57 Cruise control switch (E45)
OEM-T121-92 Throttle position sensor 2 (G188)
0V sensor
0V sensor
OEM-T121-102 Ignition coil 1 (N127)
OEM-T121-56 Brake pedal switch (F)
OEM-T121-82 Crank position sensor (G28)
OEM-T121-76 Cruise control switch (E45)
OEM-T121-75 Cruise control switch (E45)
OEM-T121-67 Crash sensor signal
0V sensor
OEM-T121-60 CAN bus high
OEM-T121-54 Road speed signal (VSS)
OEM-T121-41 A/C signal
OEM-T121-84 Throttle position sensor 1 (G187)
OEM-T121-35 Accelerator pedal position 2 (G185)
0V sensor
OEM-T121-58 CAN bus low
OEM-T121-86 Camshaft position sensor (G40)
OEM-T121-33 Accelerator pedal position 1 (G79)
OEM-T121-101 Boost pressure sensor (G31)
OEM-T121-93 Engine coolant temperature (G62)
OEM-T121-85 Intake air temperature (G42)
OEM-T121-49 Power steering pressure switch (F88)
OEM-T121-53 MAF sensor signal (G70)
OEM-T121-107 Knock sensor 2 (G66)
OEM-T121-55 Brake pedal switch (F)
5V ref
5V ref
OEM-T121-106 Knock sensor 1 (G61)
MAIN
MAIN-R
MAIN
INRelay contact input (battery + via main fuse)
OUTRelay contact output (switched +12V bus)
COIL+Relay coil positive (ignition-switched +12V)
COIL-Relay coil negative (ECU low-side driver)
NEW-BATT
Relay contact output (switched +12V bus) · 4 pins
Relay coil positive (ignition-switched +12V)
SP-GND · 8 pins
SP-14V · 3 pins
SP-0V · 14 pins
SP-GND · 10 pins
◯New feed: NEW-BATT
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.