OBD-II (SAE J1962) Connector Pinout
The 16-pin car diagnostic port — CAN, K-line, power, and ground.
Overview
OBD-II is the 16-pin (J1962) diagnostic connector in every car sold since the mid-1990s (1996+ US). It exposes one or more of several bus protocols plus battery power and ground. Modern vehicles use CAN bus (pins 6 and 14).
Several pins are manufacturer-discretionary, so what's populated varies by car. Pin 16 is always +12V (battery, unswitched) and pins 4/5 are ground.
Pinout
| Pin | Name | Function | Description |
|---|---|---|---|
| 1 | Manufacturer | Vendor-specific. | |
| 2 | J1850 Bus+ | DATA | SAE J1850 PWM/VPW +. |
| 3 | Manufacturer | Vendor-specific. | |
| 4 | Chassis Ground | GND | Chassis ground. |
| 5 | Signal Ground | GND | Signal ground. |
| 6 | CAN High | CAN | ISO 15765-4 CAN-H. |
| 7 | K-Line | DATA | ISO 9141-2 / ISO 14230 K-line. |
| 8 | Manufacturer | Vendor-specific. | |
| 9 | Manufacturer | Vendor-specific. | |
| 10 | J1850 Bus− | DATA | SAE J1850 PWM −. |
| 11 | Manufacturer | Vendor-specific. | |
| 12 | Manufacturer | Vendor-specific. | |
| 13 | Manufacturer | Vendor-specific. | |
| 14 | CAN Low | CAN | ISO 15765-4 CAN-L. |
| 15 | L-Line | DATA | ISO 9141-2 L-line (optional). |
| 16 | Battery +12V | POWER | Unswitched battery power. |
Notes
- Modern cars use CAN on pins 6 (H) and 14 (L) — the most common protocol today.
- Pin 16 is always live (12V) even with ignition off — mind current draw.
Reference: SAE J1962 OBD-II pinout· verified 2026-06-21