Testing Procedure

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

1. Record Customer Complaint
   
   Ensure all customer complaints or observations are recorded. Test drive vehicle with customer when necessary for malfunction verification.
2. DLC3 Inspection
   
   Connect the hand-held tester to the Data Link Connector No. 3 (DLC3) located under left side of instrument panel, left of steering column. See Fig 1. If the display indicates a communication fault in the tool, inspect the DLC3. See DATA LINK CONNECTOR NO. 3 INSPECTION  under SCAN TOOL PROBLEMS.
3. Retrieve DTCs and Freeze Frame Data
   
   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  and FREEZE FRAME DATA  .
4. Clear DTCs and Freeze Frame Data
   
   Using Toyota hand-held tester or scan tool, clear DTCs and freeze frame data from ECM. See CLEARING DIAGNOSTIC TROUBLE CODES .
5. Visual Inspection
   
   Inspect all electrical connectors and wiring for suspected circuit or component. Ensure all electrical connections are clean and tight.
6. Check Mode Diagnosis
   
   Set the check (test) mode diagnosis. See TWO-TRIP DETECTION LOGIC .
7. Confirm Symptoms
   
   If the engine does not start, perform steps  8 and  9 first. If a malfunction does not occur, simulate symptom and go to the next step. If a malfunction occurs, go to next step.
8. DTC Check
   
   Check DTC. See SYSTEM OVERVIEW . If there is a malfunction code, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS  table under DIAGNOSTIC TROUBLE CODE DEFINITIONS, then go to step  11. If there is no code, go to the next step.
9. Basic Inspection
   
   Perform basic inspection. See BASIC INSPECTION . If wrong parts are not confirmed, go to the next step. If the wrong parts are confirmed, inspect parts and go to step  14.
10. Determine Symptom
    
    Refer to problem symptom table. See SYMPTOM DIAGNOSIS under SYMPTOMS in TROUBLE SHOOTING - NO CODES article. If the wrong circuit is confirmed, go to the next step. If the wrong parts are confirmed, inspect parts and go to step  14.
11. ECM Power Source Circuit Inspection
    
    Check the ECM power source circuit. See ENGINE CONTROL MODULE POWER SOURCE CIRCUIT under COMPUTERIZED ENGINE CONTROLS in SYSTEM & COMPONENT TESTING - 4-CYLINDER article.
12. Circuit Inspection
    
    If malfunction is not confirmed, go to the next step. If malfunction is confirmed, go to step  14.
13. Intermittent Problem Check
    
    Check for intermittent problems. See INTERMITTENT PROBLEMS CHECK (HAND-HELD TESTER ONLY) .
14. Verification Procedure
    
    Identify problem and make necessary adjustments and repairs. After repairs have been completed, clear all DTCs from ECM. See CLEARING DIAGNOSTIC TROUBLE CODES . Perform road test. Ensure no DTCs are present and all symptoms and/or complaints have been repaired.

Fig 1: Connecting Hand-Held Tester To DLC3

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