Hard Failures

Hard failures cause Malfunction Indicator Light (MIL) to illuminate and remain on until the malfunction is repaired. If light comes on and remains on (light may flash) during vehicle operation, cause of malfunction must be determined using trouble code charts. See TROUBLE CODE CHARTS  . If a sensor fails, Engine Control Module (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 be encountered.