OBD2 Port Pinout — All 16 Pins Explained
All CarsGeneral GuidesAll yearsData Lines (CAN)Updated 2026-10-10The OBD2 port is the 16-pin socket under the dashboard where you plug in a scanner. Its main pins are the same on every car built for OBD2 (USA from 1996, Europe petrol from 2001, diesel from 2004). If the scanner won't connect, these pins are the first thing to check.
Pinout — pin number & wire colour
OBD2 / SAE J1962 socket (16 pins)
| Pin | Name | What it does |
|---|---|---|
| 2 | J1850+ | J1850 bus + (older Ford / GM). |
| 4 | CGND | Chassis ground. |
| 5 | SGND | Signal ground. |
| 6 | CAN-H | CAN high — most cars from 2008. |
| 7 | K-LINE | K-line (ISO 9141 / KWP2000) — many Asian & European cars. |
| 10 | J1850- | J1850 bus − (PWM, older Ford). |
| 14 | CAN-L | CAN low — pairs with pin 6. |
| 15 | L-LINE | L-line (ISO 9141) — some older cars. |
| 16 | BAT+ | Battery +12 V, always on (scanner power). |
| ? | 1, 3, 8, 9, 11, 12, 13 | Maker's own use (different on each brand). |
OBD2 socket — pin positions
- Top row is pins 1–8 (left to right), bottom row is 9–16, looking into the car's socket.
- Pin 16 must have 12 V all the time. If not, check the cigarette-lighter / accessory fuse — the OBD port often shares it.
- Pins 4 and 5 must be ground (0 Ω to body).
- Pins 6 and 14 carry CAN data. Pin 7 is used on many older Toyota, Suzuki, Hyundai and European cars.
🧰 Tools you need
- Digital multimeter
- OBD2 scanner (ELM327 or better)
- 12 V test light
- Back-probe pins / jumper wires
Common problems & quick checks
| Problem | Likely cause | What to check |
|---|---|---|
| Scanner has no power | No 12 V on pin 16, or no ground on 4/5 | Check the accessory / cigarette-lighter fuse. Measure pin 16 to pin 4. |
| Scanner on, but 'No communication' | Wrong protocol, or CAN / K-line fault | Pick the right car in the scanner. Battery OFF: pin 6 to 14 should be about 60 Ω. |
| Works on other cars, not this one | Bent or pushed-back pin in the socket | Look into the socket with a torch; gently straighten pins. |
Related trouble codes
Networkhigh
U0001 — High Speed CAN Communication Bus
A module found a problem on the high-speed CAN data wires.
NetworkhighU0073 — Control Module Communication Bus "A" Off
A module stopped talking because the data bus is shut down or faulty.
NetworkhighU0100 — Lost Communication With ECM/PCM "A"
Other computers can no longer hear the engine computer (ECM).
NetworkmediumU0121 — Lost Communication With ABS Control Module
The ABS computer stopped sending messages on the data wires.
NetworkmediumU0155 — Lost Communication With Instrument Panel Cluster
Another computer in the car stopped getting messages from the meter. The meter has no power, no ground, or is not connected to the data wires.
This is a simplified drawing for learning. Pin numbers and colours can change by model and year — check the service manual for your exact car before repairing.