Important: Perform the following steps in sequence BEFORE proceeding to the engine vibration analysis tables.
- Perform the
Vibration Analysis - Road Testing
table in order to duplicate and effectively diagnose the customer's concern.
- If powertrain related DTCs are present, there may be a powertrain performance condition present which could be a contributing cause to the customer's concern. Using a scan tool, determine if any DTCs are set. If DTCs have been set, refer to
Diagnostic Starting Point - Engine Controls
in Engine Controls- 7.8L
- After the Vibration Analysis -- Road Testing is complete and there are no DTCs which affect the customer's concern, go to
Vibration Analysis - Engine/Accessory Isolation
.