Honda pre-OBD2 diagnostic connector is a simple 2 or 3-pin connector usually located in the passenger footwell or under the dashboard. Bridging the diagnostic pin to ground with a jumper activates blink code output.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | MES | Multiplex ECU Service line | BUS |
| 2 | GND | Ground | GND |
| 3 | VCC | 12V power optional | PWR |