Sharperrover- "watch dog" probably refers to a watchdog timer, a timing circuit that is used generally by the ECU as a subroutine as it 'checks' all of the inputs coming into it. Once all relays have been checked, the watchdog timer resets itself. If for some reason one of the relays did not send out a signal, the watchdog timer would 'time out' and alert the ECU of a input failure. At least that is the way I understand it. Sometimes, due to acts of god, solar flares, whatever, the watchdog timer will not record all the relays as it cycles through even though nothing is wrong. This condition will clear the next time you start your car unless there is indeed a problem.