Gather Information

Gather information from all resources available to pinpoint the "when," "where," "why," and "how" of the symptom. Road test with the customer when possible to completely understand the symptom. Compare the symptom to a similar vehicle to verify this is an abnormal condition. Find out (when applicable) grade of fuel and where purchased, maintenance history (oil changes, etc.), typical driving cycle, etc. Perform a bulletin search focusing on specific symptoms.