I am looking to hardwire in a bluetooth OBD-II scanner into my car (2013 Subaru Impreza WRX) so that I can display gauges on my phone with Torque Pro.

My car has a CAN-H and CAN-L in the radio harness (pin 11 and 12) that was used for the factory navigation unit that I plan to tap by adding the pins to the aftermarket radio harness.

I also bought a donor OBD-II splitter I plan to use to connect the bluetooth dongle to. I am going to cut off the splitter and wire the two CAN bus wires into pins 6 and 14 on the splitter. Power will be accessory power wired through a switch (and fused on a new dedicated circuit).

Do I need the K-line and L-line (pins 7 and 15) for the dongle to work with Torque?

I plan to wire Cgnd (OBD pin 4) to a ground on the dash subframe and Sgnd (OBD pin 5)to the radio harness ground (I figure the OEM headunit grounded through here). Is this OK?

  • 1
    Why this approach? Bluetooth dongles are very compact, why not just leave it in the original port all the time and take it out if you ever need to plug in a different scanner? – GdD Mar 29 at 8:59
  • The port is battery power and on all the time, so I would rather not leech battery power. I was just hoping to be able to flip it on with a switch or put it on an accessory circuit so it only powers up with the ignition. – Wrxeter Mar 31 at 6:44
  • And for anyone wondering, Torque app wont work without the K-line and L-line pin. The app will just continually cycle through communication modes and never connect. – Wrxeter Mar 31 at 6:46

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