I had the exact same problem with the exact same cable. John at 1320 Electronics is super! Its not the cable, its a problem with the car. He built me a few special cables with extra filters then credited the standard cable towards the Bluetooth version. All my problems disappeared, plus now I can data log with my phone using his app. The Bluetooth ALDL is not as susceptible to ground interference. John has been great through the whole thing so I cant say enough good about his products. He is a member here. His user name is 1320_john. You can contact him on his website too.