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
Constant +12V
ECU power +14V (main relay)
T4-C3-25 PWM 7
T4-C2-4 Digital 1
T4-C2-14 Digital 4
T4-C1-5 PWM 1
T4-C3-10 PWM 8
T4-C2-15 Digital 5
T4-C1-4 PWM 2
T4-C1-3 PWM 3
T4-C3-9 Lambda 1 Heater Negative
T4-C2-34 Analogue 9
OEM-1
Stock ECU being replaced
AConstant +12V
BECU power +14V (main relay)
EMalfunction indicator lamp (MIL)
FBrake switch
GPower steering pressure switch
ICondenser fan relay
OAlternator control
PA/C request
RCooling fan relay
SA/C clutch relay
UFront O2 heater
VNeutral switch
T4-C3-17 Analogue 7
T4-C2-25 Thermistor 2
T4-C2-6 Analogue 4
T4-C2-2 Wheel 1
T4-C2-7 Thermistor 1
T4-C2-22 Cam 1
5V ref
T4-C2-12 Crank
T4-C2-10 Analogue 1
OEM-2
Stock ECU being replaced
AFuel tank pressure
BIntake air temperature (IAT)
CFront O2 signal
DVehicle speed
ECoolant temperature (ECT)
HCam position (CMP)
I+5V sensor supply
JCrank position (CKP)
LMass air flow (MAF)
GND
GND
GND
T4-C2-5 Analogue 3
0V sensor
T4-C1-10 Coil 1
T4-C1-18 Coil 2
T4-C2-3 Analogue 10
T4-C2-19 Analogue 6
T4-C3-18 Analogue 8
ISC valve +14V feed
T4-C3-22 PWM 4
T4-C3-24 PWM 6
T4-C2-1 Analogue 2
T4-C3-23 PWM 5
T4-C1-9 Injector 1
T4-C1-17 Injector 2
T4-C1-34 Injector 3
T4-C1-25 Injector 4
OEM-3
Stock ECU being replaced
APower ground
BPower ground
CPower ground
EThrottle position (TPS)
FSignal ground
GIgnition 1 (coils 1+4, wasted spark)
HIgnition 2 (coils 2+3, wasted spark)
IClutch switch
JRear O2 signal
KFuel level
MISC valve +14V feed
NFuel pump relay
OISC valve low side
SPressure sensor (Mazda: EGR boost sensor)
VRear O2 heater
WInjector 1
XInjector 2
YInjector 3
ZInjector 4
T4
T4-C1
T4
3PWM 3
4PWM 2
5PWM 1
9Injector 1
10Coil 1
13Power Ground 1
14Power Ground 2
17Injector 2
18Coil 2
25Injector 4
31Ignition 12v In
34Injector 3
OEM-1-S A/C clutch relay
OEM-1-R Cooling fan relay
OEM-1-I Condenser fan relay
OEM-3-W Injector 1
OEM-3-G Ignition 1 (coils 1+4, wasted spark)
GND
GND
OEM-3-X Injector 2
OEM-3-H Ignition 2 (coils 2+3, wasted spark)
OEM-3-Z Injector 4
Ignition 12v In
OEM-3-Y Injector 3
T4-C2
T4
1Analogue 2
2Wheel 1
3Analogue 10
4Digital 1
5Analogue 3
6Analogue 4
7Thermistor 1
10Analogue 1
12Crank
14Digital 4
15Digital 5
19Analogue 6
21Sensor Ground
22Cam 1
245v Output
25Thermistor 2
33Sensor Ground
34Analogue 9
OEM-3-S Pressure sensor (Mazda: EGR boost sensor)
OEM-2-D Vehicle speed
OEM-3-I Clutch switch
OEM-1-F Brake switch
OEM-3-E Throttle position (TPS)
OEM-2-C Front O2 signal
OEM-2-E Coolant temperature (ECT)
OEM-2-L Mass air flow (MAF)
OEM-2-J Crank position (CKP)
OEM-1-G Power steering pressure switch
OEM-1-P A/C request
OEM-3-J Rear O2 signal
0V sensor
OEM-2-H Cam position (CMP)
5V ref
OEM-2-B Intake air temperature (IAT)
0V sensor
OEM-1-V Neutral switch
T4-C3
T4
9Lambda 1 Heater Negative
10PWM 8
17Analogue 7
18Analogue 8
22PWM 4
23PWM 5
24PWM 6
25PWM 7
26Permanent 12v
OEM-1-U Front O2 heater
OEM-1-O Alternator control
OEM-2-A Fuel tank pressure
OEM-3-K Fuel level
OEM-3-N Fuel pump relay
OEM-3-V Rear O2 heater
OEM-3-O ISC valve low side
OEM-1-E Malfunction indicator lamp (MIL)
Permanent 12v
SP-14V · 4 pins
SP-GND · 6 pins
SP-0V · 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.
45 / 45 connections
Columns ▾
Lengths need a layout. Add bundles in Layout.
Not set yet: signal, colour, stripe, ident.
| Wire | From | To | Signal | Gauge | Colour | Stripe | Ident | Flags | |
|---|---|---|---|---|---|---|---|---|---|
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — | |||||||||
| — |