OBD-I is the umbrella term for proprietary pre-standard diagnostic connectors used before OBD-II became mandatory in 1996. Each manufacturer had their own proprietary connector, pin count, and communication protocol.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | DIAG | Diagnostic signal line | BUS |
| 2 | GND | Ground | GND |
| 3 | VCC | 12V power | PWR |
OBD-I is the umbrella term for proprietary pre-standard diagnostic connectors used before OBD-II became mandatory in 1996. Each manufacturer had their own proprietary connector, pin count, and communication protocol.