Abstract: An apparatus is disclosed including an internal combustion engine, a number of sensors configured to detect operating parameters of the engine, and art engine control system responsive to the sensors to regulate engine operation. The control system includes a controller operatively coupled to a nonvolatile memory and has an interface capable of receiving operator input to customize aspects of a diagnostic data collection routine embedded in the control system. The routine responds to this input to selectively establish a data collection trigger, the nature of the information to be stored in the nonvolatile memory in response to this trigger, and the rate of storage of this information in the memory. The trigger may be externally generated with an operator-controlled triggering device coupled to the control system or internally generated as a function of one or more of the operating parameters.