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using ELM 327 or similar bluetooth dongle on GM 10 pin ALDL diagnostics?

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  • using ELM 327 or similar bluetooth dongle on GM 10 pin ALDL diagnostics?

    So I own a 1991 C20NE Opel Calibra with mapped and chipped ECU. I'm bit tired of connecting OP-COM to the ALDL and laptop every time I have to clear some fault codes or track live data after making some tweaks on my engine. For this question I need some diagnostics genius. Calibra and opel Vectra A have the same engine and the same ECU. The friend of mine tried to connect ELM 327 using an ALDL to OBD2 adapter and couldn't get any readings. Is there someone that tried to pull this on any GM 10 pin ALDL diagnostics, and if he did could he tell me how. Any idea anyone could give would be helpful.

  • #2
    The pin out on the car socket itself might be different from the pins on your adapter. fundamentally you only need 12v, ground and signal to read and erase the faults.

    So Pin A on the ALDL is (join) OBD pins 4 and 5. These are the ground.
    Pin G is terminal 7 on OBD, it's the K line Signal (the L line signal is ALDL Pin K which is pin 15 on OBD)
    pin F is 12V power, which is OBD pin 16.

    So if you have a schematic for your adapter, make sure it's got the right pins connected
    I stripped my car out so much it now has 49/49 weight distribution.

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    Martin's Kei to success



    • #3
      Ok, I'll try that and post the result as a comment.


      • #4
        I had a VT that I think might be a similar situation. Used a OBD plug but wasn't compliant with any OBD protocol. My bluetooth ELM327 would power-up but not connect. I remember seeing some home-brew circuits to 'bit'bang' an interface with a serial port