OBD-II Connector Pinout Reference
Complete pinout for the SAE J1962 16-pin Diagnostic Link Connector (DLC) used on every 1996+ light-duty vehicle sold in the U.S. Whether you're troubleshooting a dead scanner, probing a protocol, or hunting the port on an unfamiliar car, this is the reference.
Connector Layout (J1962 16-pin)
The OBD-II port is a trapezoidal 16-pin connector. Viewed looking at the face of the female port (as mounted in the car), pins are numbered 1-8 across the top row and 9-16 across the bottom row, left to right:
| Row | Pin 1 / 9 | Pin 2 / 10 | Pin 3 / 11 | Pin 4 / 12 | Pin 5 / 13 | Pin 6 / 14 | Pin 7 / 15 | Pin 8 / 16 |
|---|---|---|---|---|---|---|---|---|
| Top | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| Bottom | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 |
Pin 16 is always in the bottom-right corner when looking at the port from the driver's footwell.
Pin Function Reference
Not every pin is populated on every vehicle -- manufacturers only wire the pins their protocol uses. Pins 4, 5, and 16 are always present (ground and power). The others vary by protocol.
| Pin | Function | Standard / Notes |
|---|---|---|
| 1 | Vendor-specific | GM low-speed single-wire CAN (GMLAN, SAE J2411) on many models; switched ignition on some others |
| 2 | J1850 Bus+ | SAE J1850 PWM (Ford) / VPW (GM) -- pre-2008 |
| 3 | Vendor-specific | Ford MS-CAN High, GM use varies |
| 4 | Chassis ground | Always present; bonded to body |
| 5 | Signal ground | Always present; common reference for data lines |
| 6 | CAN High (CAN-H) | ISO 15765-4 / SAE J2284 -- required on all 2008+ vehicles |
| 7 | K-Line | ISO 9141-2 / ISO 14230 KWP2000 (mainly European, Asian pre-2008) |
| 8 | Vendor-specific | Varies by make (e.g. second K-line or ignition sense); often unused |
| 9 | Vendor-specific | Varies by make (e.g. older GM ALDL serial on some models) |
| 10 | J1850 Bus- | Only used on SAE J1850 PWM (Ford) -- leave unused on VPW/GM |
| 11 | Vendor-specific | Ford MS-CAN Low on some models |
| 12 | Vendor-specific | Rarely populated |
| 13 | Vendor-specific | Rarely populated |
| 14 | CAN Low (CAN-L) | ISO 15765-4 -- paired with pin 6 for CAN bus |
| 15 | L-Line | ISO 9141-2 (optional second K-Line wake-up line) |
| 16 | Battery +12V | Always present; unswitched battery power (fuse size varies by vehicle -- often shared with the accessory socket) |
The Five OBD-II Protocols
OBD-II uses five physical protocols. Since 2008, CAN (ISO 15765-4) has been mandatory in the U.S. -- but older vehicles use one of the four legacy protocols, and your scanner needs to support it.
| Protocol | Standard | Pins Used | Used By |
|---|---|---|---|
| PWM | SAE J1850 PWM (41.6 kbps) | 2, 10 | Ford 1996-2003 (Ford, Lincoln, Mercury, Mazda) |
| VPW | SAE J1850 VPW (10.4 kbps) | 2 | GM 1996-2003 (Chevy, Buick, Cadillac, Pontiac, etc.) |
| ISO 9141-2 | ISO 9141-2 (10.4 kbps) | 7, optional 15 | Chrysler, European, most Asian 1996-2003 |
| KWP2000 | ISO 14230-4 (10.4 kbps) | 7, optional 15 | Many European 2003-2007 |
| CAN | ISO 15765-4 (250 or 500 kbps) | 6, 14 | All 2008+ vehicles sold in U.S. |
Quick test: If pin 6 and pin 14 are populated, your car uses CAN. If pin 2 is populated but not pin 10, it's VPW (GM). If both 2 and 10 are populated, it's PWM (Ford). If only pin 7 (and sometimes 15) is populated, it's ISO 9141-2 or KWP2000.
Which Protocol Does My Vehicle Use?
| Make | Model Years | Protocol |
|---|---|---|
| All makes | 2008+ | CAN (ISO 15765-4) |
| Ford / Lincoln / Mercury | 1996-2003 | PWM (J1850) |
| Ford / Lincoln / Mercury | 2003-2007 | CAN (early adoption) |
| GM (Chevy, GMC, Buick, Cadillac, Pontiac) | 1996-2005 | VPW (J1850) |
| GM | 2005-2007 | Mix -- CAN or VPW |
| Chrysler / Dodge / Jeep | 1996-2004 | ISO 9141-2 |
| Chrysler / Dodge / Jeep | 2005-2007 | CAN (early adoption) |
| Toyota / Lexus / Scion | 1996-2003 | ISO 9141-2 |
| Toyota / Lexus / Scion | 2004-2007 | CAN (early adoption) |
| Honda / Acura | 1996-2002 | ISO 9141-2 |
| Honda / Acura | 2003-2007 | Mix -- CAN or ISO 9141-2 |
| Nissan / Infiniti | 1996-2003 | ISO 9141-2 |
| BMW / Mini | 1996-2003 | ISO 9141-2 |
| BMW / Mini | 2004-2007 | KWP2000 or CAN |
| Mercedes-Benz | 1996-2003 | ISO 9141-2 |
| VW / Audi | 1996-2003 | ISO 9141-2 |
| VW / Audi | 2004-2007 | KWP2000 |
| Subaru | 1996-2003 | ISO 9141-2 |
| Hyundai / Kia | 1996-2003 | ISO 9141-2 |
Where Is the OBD-II Port?
The SAE J1962 standard requires the DLC to be within 2 feet (0.61 m) of the steering wheel and accessible without tools. Most of the time it's right there. Sometimes it isn't.
Common locations
- Under the dash, driver's side, near the steering column. The default location on most vehicles.
- Under the dash, center or passenger side. Common on some Chrysler, Honda, and older Ford models.
- Behind an ashtray or coin tray. Typical on some BMWs and Mercedes models.
Unusual locations by make
| Make / Model | Port Location |
|---|---|
| Subaru (most) | Lower dash, above the driver's left knee, facing down |
| BMW 3 Series (E46, E90) | Under the dash on the driver's side, above the pedals |
| BMW (pre-2001) | Round 20-pin port in the engine bay -- requires OBD-I-to-OBD-II adapter |
| Mercedes-Benz (some) | Behind a plastic cover near the center console or under the armrest |
| Volvo S40 / V40 | Behind the ashtray on the center console |
| Volvo S60 / S80 (older) | Under the ashtray; lift the tray to reveal |
| VW / Audi | Usually near the driver's knee; some hidden behind a coin slot cover |
| Porsche 911 (996, 997) | Driver's footwell, behind a small plastic flap |
| Saab 9-3 / 9-5 | Passenger footwell, behind a trim panel |
| Jaguar XJ / XK | Passenger side under glove box, or behind center console |
| Land Rover / Range Rover | Under driver's side dash; sometimes hidden behind a panel |
| Mini Cooper (R50, R56) | Under steering column, hidden behind a small access panel |
| Chevy Corvette (C5, C6) | Driver's side near the e-brake, facing the driver's seat |
Can't find the port? The Equipment and Tool Institute maintains a free DLC location database, and the under-dash EPA emissions sticker on 1996+ U.S.-market vehicles usually mentions it.
Troubleshooting a Dead OBD Port
- No power to scanner. Check battery voltage at pin 16 -- should read ~12V with key off. If 0V, check the OBD-II fuse (often labeled "Cigar," "Data Link," or "DLC") in the dash fuse box.
- Scanner powers on but won't connect. Verify you're on the right protocol. Low-cost OBD tools sometimes only speak CAN -- won't work on pre-2008 vehicles with PWM/VPW/ISO.
- Intermittent connection. Check the scanner cable and the port terminals for pushed-back or corroded pins. Port sits near the driver's feet and gets kicked.
- Scanner works sometimes but drops. Low battery voltage causes loss of CAN bus sync. Put a maintainer on the battery before long diagnostic sessions.
- Chassis ground (pin 4) bad. Usually shows as garbled data or scanner reboot. Test continuity from pin 4 to a known chassis point.