OBD-II Connection

Pinouts: Looking at female OBD-II (SAE J1962 spec) connector/socket, (on all Subaru diesel models so far) located between steering wheel and pedals.

Euro 4 models

\          3   4   5   6   7   8   /
 \                     14      16 /

Picture from an Euro 4 Impreza diesel:

Euro 5/6 models

Pin 3 not available anymore, though, not important.

\              4   5   6   7   8   /
 \                     14      16 /

Pin description

Pin Name Description
3 Proprietary Pull to GND → test mode ON (when ignition turned ON), same effect as test mode connector.
4 Chassis GND Pins 4 & 5 are connected internally.
5 Signal GND
6 CAN-High of CAN high speed bus
7 K-Line Serial communication, multiple control units can be reached.
8 Proprietary Ignition ON via relay. Could power interface with this one instead of pin 16, see example.
14 CAN-Low of CAN high speed bus
16 Battery+ Normally interfaces draw power from this one, so do not leave hardware connected for many days without charging the battery!


Protocol Pin Baudrate
CAN, OBD-II, SSM2 via CAN, Extended OBD-II 6 + 14 500,000
KWP 2000 / ISO 14230 via Serial 7 10,400
SSM2 via Serial 7 4,800

See also page Protocols listing all known Subaru relevant (petrol & diesel) protocols.


3 responses to “OBD-II Connection

  1. Great info, amazing software, excellent work!!!

    I have a MY10 Forester and I am searching for a OBD-II interface. Do you recommend any?


    • Try to find out if you’ve got Euro4 or Euro5 model. Unfortunately model year doesn’t seem to be enough info on this one.
      Plus it depends on what you want to do.

      If you have E4 model and only want to log SSM2 data, cheap serial converter interface (that supports K-Line 4800 baud) is enough. See FreeSSM and RomRaider sites for more details on these.

      CAN/ISO15765 protocols like OBD-II, SSM2 via CAN, Extended OBD-II (Euro5 only) need CAN capable device. In this case, Tactrix Openport 2.0 is a good choice, reasonable price. Just note that it might not be fully J2534 compliant, might not work with all commercial apps. If you want to use open source software like RomRaider it’s probably best choice, well tested.


  2. hi there, great site! thank you very much for all the detailed information!
    since i’d problems with my euro 5 legacy diesel a couple of times i’m trying to get real time informations for the DPF through OBD. i’m interested in the current DPF filling state and the current exhaust temp the DPF gets.

    this information has to “easy to read while driving” so displaying the information through an android app like torque would be the best solution for me. i tried different low priced obd adapter but couldn’t find supported PIDs regarding DPF or exhaust temp in neither torque nor dashcmd.
    do you guys know if there is a OBD adapter / android app combination that could display DPF filling state plus exhaust temp ?
    thank you!


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