Diagnostic Aids

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Excessive vibration from sources other than the engine could cause DTC P0300 to set. The following are possible sources of vibration:
- Thickness variation of the brake rotors-Refer to Symptoms - Hydraulic Brakes in Hydraulic Brakes.
- The drive shaft not balanced-Refer to Vibration Analysis - Driveline in Vibration Diagnosis and Correction.
- Worn or damaged accessory drive belt-Refer to Symptoms - Engine Mechanical in Engine Mechanical.
There may be more or less cylinders actually misfiring than indicated by the scan tool.