Hard Failures
WARNING: This page is about a different car, the 2000 Saturn LW1, 2000 Saturn LS1, and 2000 Saturn LS. However, it is still accessible from the selected car via links, so may be relevant.
Most hard failures cause MIL to illuminate and remain on until malfunction is repaired. If MIL illuminates and remains on (light may flash) during vehicle operation, cause of malfunction must be determined. See DIAGNOSTIC PROCEDURE .
If a sensor fails, PCM will use a substitute value in its calculations to continue engine operation. In this condition, vehicle is functional, but it will most likely display degraded driveability.