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
  
  Using Toyota hand-held tester or scan tool, retrieve Diagnostic Trouble Codes (DTC) from Engine Control Module (ECM) and record any freeze frame data (if applicable). See RETRIEVING DIAGNOSTIC TROUBLE CODES .
• Clear Diagnostic Trouble Codes
  
  Using Toyota hand-held tester or scan tool, clear DTCs and freeze frame data from ECM. See CLEARING DIAGNOSTIC TROUBLE CODES .
• Visual Inspection
  
  Inspect all electrical connectors and wiring for suspected circuit or component. Ensure all connections are clean and tight.
• Confirm Symptoms & Diagnostic Trouble Codes
  
  Perform road test. Determine if original symptoms still exist. Using scan tool or Toyota hand-held tester, retrieve DTCs from ECM. See RETRIEVING DIAGNOSTIC TROUBLE CODES .
• Diagnose & Repair Diagnostic Trouble Codes
  
  Perform appropriate DTC test listed under DIAGNOSTIC TESTS as necessary. For DTC descriptions, see DIAGNOSTIC TROUBLE CODE DEFINITIONS  table under DIAGNOSTIC TROUBLE CODE DEFINITIONS. If no DTCs are present and a no start condition exists, proceed to BASIC DIAGNOSTIC PROCEDURES - 4-CYLINDER article. If no DTCs are present and a driveability condition exists, proceed to TROUBLE SHOOTING - NO CODES article for diagnosis by symptom (i.e., ROUGH IDLE, ENGINE STALLS, etc.).
• Verification Procedure
  
  After repairs have been completed, clear all DTCs from ECM. See CLEARING DIAGNOSTIC TROUBLE CODES . Perform road test. Ensure no DTCs exist and all symptoms and/or complaints have been repaired.