Not to be confused with ODB, OBD stands for On Board Diagnostics and is used for analyzing and diagnosing vehicles. It’s the thing your mechanic plugs into to find out why you’ve got a blinking engine light.

Technically, OBD uses CAN bus and, hey, whaddya know, we’ve got some CAN-capable microcontroller boards here at Adafruit so this OBD Plug (16-pin) to DE-9 (DB-9) Socket Adapter Cable will come in super handy when you want to attach one of our CAN boards to your car!

On one end is a 16-pin OBD plug that goes right into your car’s port. The other end is a DE-9 ‘CAN bus’ connector. Sometimes DE-9 connectors are referred to as DB-9. Technically that’s the wrong name, but it’s so ingrained that most people only know the connector as DB-9.

Note: Despite having a serial port-looking end, this cable is not meant to be plugged directly into a computers serial port. It is meant to plug into a hardware CAN BUS interface. It does not contain circuitry or any kind of translator, it only re-wires a OBD plug into a DB-9 plug

Here’s the pinouts, you’ll need to match this up against the CAN board you have to make sure the CAN H, CAN L and GND in the right spots.

• DB-9 pin 1 connects to OBD pin 11
• DB-9 pin 2 connects to OBD pin 14 : CAN L
• DB-9 pin 3 connects to OBD pin 5 : Signal Ground
• DB-9 pin 4 connects to OBD pin 8
• DB-9 pin 5 connects to OBD pin 1
• DB-9 pin 6 connects to OBD pin 4 : Chassis Ground
• DB-9 pin 7 connects to OBD pin 6 : CAN H
• DB-9 pin 8 connects to OBD pin 3
• DB-9 pin 9 connects to OBD pin 16 : Battery Power

Not to be confused with ODB, OBD stands for On Board Diagnostics and is used for analyzing and diagnosing vehicles. It’s the interface your mechanic uses to diagnose issues such as blinking engine lights.

This OBD Plug (16-pin) to DE-9 (DB-9) Socket Adapter Cable is 1 meter long and designed to connect the OBD port on your vehicle to a DE-9 CAN bus connector on your CAN-capable microcontroller boards.

The cable features:

• 16-pin OBD plug for car port connection
• DE-9 (DB-9) socket adapter, often used in CAN bus interfaces
• Pinouts matching for CAN H, CAN L, and Ground signals

Important Note: Despite the DE-9 resembling a serial port connector, this cable is intended strictly for CAN BUS hardware interfaces. It contains no circuitry or signal translationit simply rewires the OBD plug to the DB-9 connector.

Pin connections are as follows:

• DB-9 pin 1 OBD pin 11
• DB-9 pin 2 OBD pin 14 (CAN L)
• DB-9 pin 3 OBD pin 5 (Signal Ground)
• DB-9 pin 4 OBD pin 8
• DB-9 pin 5 OBD pin 1
• DB-9 pin 7 OBD pin 6 (CAN H)
• DB-9 pin 8 OBD pin 3
• DB-9 pin 9 OBD pin 16 (Battery Power)