Symptom Troubleshooting Versus DTC Troubleshooting

Symptom Troubleshooting Versus DTC Troubleshooting
Some symptoms will not trigger diagnostic trouble codes (DTCs) or cause the D indicator to blink. If the malfunction indicator lamp (MIL) was reported ON or the D indicator has been blinking, check for DTCs. If the vehicle has an abnormal symptom, and there are no DTCs stored, go to the Symptom Troubleshooting Index. Check the list of probable cause(s) for the symptom in the sequence listed, until you find the problem.