Diagnostic Procedure

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA (MODE 2)/SNAPSHOT DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED Have the FREEZE FRAME DATA (Mode 2)/snapshot data and DIAGNOSTIC MONITORING TEST RESULTS (catalyst related) been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA (Mode 2)/snapshot data and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY Verify related Service Bulletins and/or on-line repair information availability. Is any related repair information available?	Yes	Perform repair or diagnosis according to the available repair information. If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	VERIFY RELATED PENDING CODE AND/OR DTC Switch the ignition to off, then to ON (engine off). Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure. (See ON-BOARD DIAGNOSTIC TEST .) Are any other PENDING CODEs and/or DTCs present?	Yes	Go to the applicable PENDING CODE or DTC inspection. (See DTC TABLE .)
3		No	Go to the next step.
4	INSPECT FOR LEAKAGE FROM EXHAUST SYSTEM Visually inspect for exhaust gas leakage in the exhaust system. Is there exhaust gas leakage?	Yes	Repair or replace the malfunctioning part according to the inspection results, then go to Step 7.
4		No	Go to the next step.
5	INSPECT INSTALLATION OF A/F SENSOR AND HO2S Inspect installation of A/F sensor and HO2S. Are the A/F sensor and HO2S installed securely?	Yes	Go to the next step.
5		No	Retighten the A/F sensor and/or HO2S, then go to Step 7. (See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION .) (See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION .)
6	VERIFY WHETHER MALFUNCTION IS IN TWC OR ELSEWHERE Perform the Idle Mixture Inspection. (See ENGINE MECHANICAL TUNE-UP .) Is there any malfunction?	Yes	Perform the symptom troubleshooting "NO. 15 EMISSION COMPLIANCE". (See NO. 15 EMISSION COMPLIANCE .) If there is any malfunction: Repair or replace the malfunctioning part according to the inspection results. If there is no malfunction: Replace the TWC. (See ENGINE EXHAUST SYSTEM REMOVAL/INSTALLATION .) Go to the next step.
6		No	Go to the next step.
7	VERIFY DTC TROUBLESHOOTING COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE .) Perform the Drive Mode 03 (EGR System, A/F Sensor Heater, HO2S Heater, A/F Sensor, HO2S and TWC Repair Verification Drive Mode). (See OBD-II DRIVE MODE .) Is the PENDING CODE for this DTC present?	Yes	Repeat the inspection from Step 1. If the malfunction recurs, replace the PCM. (See PCM REMOVAL/INSTALLATION .) Go to the next step.
7		No	Go to the next step.
8	VERIFY AFTER REPAIR PROCEDURE Perform the "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE .) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE .)
8		No	DTC troubleshooting completed.