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 Trouble Codes  Connect appropriate OBD-II scan tester. Retrieve codes and record any freeze-frame data. See RETRIEVING TROUBLE CODES .
• Clear Trouble Codes  Clear codes using scan tester. See CLEARING 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 Trouble Codes  Perform diagnosis and repair procedures as needed. See appropriate DIAGNOSTIC TESTING. If no codes are present, proceed to TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.).
• Verification Procedure 

After repairs have been completed, clear all trouble codes. See CLEARING TROUBLE CODES . Perform road test. Ensure no trouble codes are present and all symptoms and/or complaints have been repaired.