Zero voltage on OBDII reader

Discussion in '456/550/575' started by ColGraves, Jul 31, 2018.

  1. ColGraves

    ColGraves Karting

    Aug 1, 2017
    Cos Cob, CT
    Full Name:
    C.T. Graves
    Hooked up an OBDII reader (Autel) to troubleshoot my '99 550, and failed to read from the ECU. It showed voltage of 12.2v, which seemed legit. On subsequent attempt, OBDII showed zero volts. I triple checked the connection (although, I am human, and I still could have messed this up!!!), and it appears firm and positive. Even took a photo to double check myself. I had the car turned over (running), but did kill the car and restart it after a reconnection. Anyone experience something like this? In Porsche 911's you sometimes have to fire up the hazards to keep the CAN open; curious if there is a similar crazy gotchya in the 550 world.

    These Ferrari OBDII mysteries are certainly challenging!

  2. fatbillybob

    fatbillybob F1 World Champ
    Owner Consultant

    Aug 10, 2002
    I have never heard of 550 obd issues except the time when Ferrari failed to ground them so they could be read from the obd connector. But this is 2018 and every 550 should be connected and read ready. You may try another tester. Sometimes communication from different testers gives different results. They should not bu they do. I have 3 testers!

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