Method and system for detecting faults in an electronic engine control module

A computer readable medium having instructions stored thereon for causing a computer to perform a method for detecting faults in an ECM output signal, the method including:

• incrementing an error timer when the output signal has a first status and decrementing the error timer when the output signal has a second status;
• incrementing a retry timer when the output signal has the first status and the error timer is below an error timer maximum;
• incrementing a retry counter when the retry timer reaches a maximum retry time;
• and
• reporting a first fault type if the retry counter reaches a retry limit before the error timer reaches an error timer maximum.

A system for identifying errors in ECM output signals, including:

• an error detection block configured to obtain an actual status of an output signal, the error detection block including logic configured to compare the status to an expected status, and provide a first output if the actual status is different from the expected status and a second output if the actual status is the same as the expected status;
• an error timer block including a summer configured to increment an error timer in response to the first output, decrement the error timer in response to the second output, and provide a timer state signal when the error timer reaches an error timer maximum;
• a retry processor including a retry timer and a retry counter, the retry processor being configured to increment the retry timer in response to the first output, increment the retry counter when the retry timer reaches a maximum retry time, and provide a retry status signal when the retry counter reaches a retry limit;
• and
• an error identification block coupled to the error timer block and the retry processor, the error identification block being configured to identify a first error type if the error identification block receives the retry status signal before receiving the timer state signal, and a second error type if the error identification block receives the timer state signal before receiving the retry status signal.

A system for reporting an intermittent fault in an ECM output signal, including:

• means for determining whether the output signal has an abnormal status;
• means for incrementing an error timer when the output signal has the abnormal status;
• means for controlling a retry timer to initiate a reconfiguration of the output signal if the retry timer reaches a maximum retry time;
• means for incrementing a retry counter if the retry timer reaches the maximum retry time;
• means for outputting a fault signal if the retry counter reaches a retry limit before the error timer reaches an error timer maximum;
• and
• means for reporting an intermittent fault if the outputting means outputs the fault signal.

A method of identifying a fault condition in an output signal, including the steps of:

• periodically detecting whether the output signal is normal or abnormal;
• if the output signal is abnormal, incrementing a timer;
• if the output signal is normal, decrementing a timer;
• if the timer reaches a maximum value, indicating a constant fault condition in the output signal.

A method of troubleshooting an ECM, including the steps of:

• connecting the ECM to diagnostic equipment;
• and
• receiving, at the diagnostic equipment, an indication that an output signal of the ECM has an intermittent fault;
• wherein the ECM generates the indication after re-enabling the output signal when the output signal exhibits an abnormal status.