Hard Failures

Hard failures will cause Malfunction Indicator Light (MIL) to glow and remain on until malfunction is repaired. If light comes on and remains on (light may flash) during vehicle operation, cause of malfunction must be determined using diagnostic (code) charts. If a sensor fails, ECM will use a substitute value in its calculations to continue engine operation. In this condition, vehicle is functional, but loss of good driveability will most likely occur.