Testing Procedure

To ensure correct diagnosis and repair, testing should be done in the following sequence:

• Record Customer Complaint
  
  Ensure all customer complaints or observations are recorded. Test drive vehicle with customer when necessary for malfunction verification.
• Retrieve Diagnostic Trouble Codes
  
  Connect appropriate OBD-II scan tester. Retrieve codes and record any freeze-frame data. See RETRIEVING DIAGNOSTIC TROUBLE CODES .
• Clear Trouble Codes
  
  Clear codes using scan tester. See CLEARING DIAGNOSTIC TROUBLE CODES .
• Visual Inspection
  
  Inspect all connectors of suspect circuit or component. Ensure all connections are clean and tight.
• Confirm Symptoms & Trouble Codes
  
  Perform road test. Determine if original symptoms are still present. Retrieve codes.
• Diagnose & Repair Diagnostic Trouble Codes
  
  Perform diagnosis and repair procedures as needed. See DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION . If no codes are present, proceed to TROUBLE SHOOTING - NO CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.).
• Verification Procedure
  
  After repairs have been completed, clear all diagnostic trouble codes. See CLEARING DIAGNOSTIC TROUBLE CODES . Perform road test. Ensure no codes are present and all symptoms and/or complaints have been repaired.