Hard Failures

Hard failures will cause Malfunction Indicator Light (MIL) to illuminate and remain on until problem is repaired. If MIL 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, PCM will use a substitute value in its calculations to continue engine operation. In this condition, commonly known as limp-in mode, vehicle will run, but driveability will not be optimum.