All diagnostics on a vehicle should follow a logical process. Strategy Based Diagnostics is a uniform approach for repairing all systems. The diagnostic flow is the place to start when repairs are necessary and may always be used in order to resolve a system problem. For a detailed explanation, refer to
Strategy Based Diagnosis
in General Information.
Visual/Physical Inspection
| • | Inspect for aftermarket or non-OEM devices such as, but not including; tailpipe extensions, headers, and exhaust cutouts. This could affect the operation and proper performance of the exhaust system. |
| • | Verify the exact operating conditions under which the concern exists. Note factors such as engine RPM, engine temperature, engine load, and frequency of concern. |
| • | Inspect the easily accessible or visible system components for obvious damage or conditions which could cause any symptom. |
Intermittent
Test the vehicle under the same conditions that the customer reported in order to verify the system is operating as designed.
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:
| • | Excessive smoke (diesel) |
| • | Exhaust buzz, groan, hum noise |
