I concur sounds like a can fault. PSSMart is correct the chassis can has to end stops resisters one in the ignition switch one in the engine control unit both 120 Ohms. If you Measure the can resistance when the fault is present you should have 60 Ohms on your meter the eseyest place to tap into the chassis can is at the ESP conrtol unit. Any reading other than 60 Ohms and the can bus is faulty Possible short to earth or positive. or even together