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 electrical 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 . If no DTCs are present and a no start condition exists, proceed to BASIC DIAGNOSTIC PROCEDURES - V6 & V8 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.