Symptom Troubleshooting [Engine]: Foreword

When the customer reports a vehicle malfunction, check the malfunction indicator lamp (MIL) indication and diagnostic trouble code (DTC), then diagnose the malfunction according to the following flowchart:
- If a DTC exists, diagnose the applicable DTC inspection. (See DTC TABLE .)
- If no DTC exists and the MIL does not illuminate or flash, diagnose the applicable symptom troubleshooting. (See QUICK DIAGNOSTIC CHART )
Fig 1: Identifying Diagnostic Flow Chart
Courtesy of MAZDA MOTORS CORP.