Ecu Pinout — Isuzu 4hl1

Engine Control System: Workshop Manual | PDF | Fuel Injection

| Pin No. | Wire Color | Function | Note | |---------|------------|----------|------| | A21 | Red/Yellow | Glow Plug Relay Control | ECU grounds this pin to turn on relay | | A22 | Black/White | Glow Plug Indicator Lamp | Ground to dash light | | B22 | Blue/Yellow | A/C Request Switch (Input) | 12V when A/C ON | | B23 | Green/Black | Cooling Fan Relay Control | For electric fan models | | A23 | Yellow/Black | Stop Lamp Switch (Brake pedal) | 12V when brake pressed | | A24 | White/Red | Tachometer Output (Engine speed signal) | 12V square wave, 4 pulses/rev | isuzu 4hl1 ecu pinout

Voltage of APP2 signal should be exactly half of APP1 signal ±0.1V. Engine Control System: Workshop Manual | PDF |

: High-voltage pulses sent to each of the four injectors. isuzu 4hl1 ecu pinout