Fail-Safe Function
When a malfunction has occurred in specific areas of engine and emission control system, ECM (PCM) enters "fail-safe function". When vehicle is operating in fail-safe function, ECM (PCM) allows a lower level of engine performance to be available, allowing vehicle to be driven for service. When malfunction occurs a failure signal is sent to ECM (PCM), and ECM (PCM) control over affected sensors and actuators is maintained on the basis of standard signals and/or a back-up program stored in ECM (PCM). While in fail-safe mode ECM (PCM) ignores failure signal and/or CPU inputs. ECM (PCM) will remain in fail-safe mode as long as malfunction is detected, fail-safe mode is canceled when ECM (PCM) detects normal conditions. For fail-safe function parameters, and detected item. See Fig 1 .