For older ECUs, forums are goldmines.
A typical Bosch ECU wiring diagram consists of several key components: bosch ecu wiring diagram pdf
Pin 48 (Screen/Shield) → To ECU case ground Pin 47 (BR/Black) → Sensor Ground (ECU Pin 5) Pin 43 (BL/Yellow) → Signal input (0.5V - 5V AC) For older ECUs, forums are goldmines
While PDFs are usually black and white, they denote wire colors with text abbreviations (e.g., SW/GE or BL/YE ). | | 6 | CAN High | Orange/Black | OBD / dashboard | |
| Pin # | Signal | Wire Color (example) | Function | |-------|--------|----------------------|-----------| | 1 | Ground | Brown | Sensor ground | | 2 | Injector cyl 1 | Green/Yellow | Injector trigger | | 3 | Ignition coil 1 | Black | Primary ignition | | 4 | Cam position signal | Blue/Red | Hall effect sensor | | 5 | 5V sensor supply | Red/White | To TPS, MAP, etc. | | 6 | CAN High | Orange/Black | OBD / dashboard | | ... | ... | ... | ... | | 37 | Main relay control | Brown/Red | Powers ECU |