Diagnostic Procedure

DTC P0140 DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED Have FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS (HO2S related) been recorded?	Yes	Go to the next step.
1		No	Record FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY Check for related Service Bulletins and/or online 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 AND STORED DTCS NOTE: If fuel monitor DTC, DTC P0131 or P0132 is retrieved, ignore it until P0140 is fixed. Turn ignition switch to OFF, then ON (Engine off). Verify pending and stored DTCs using the WDS or equivalent. Is other DTC present?	Yes	Go to appropriate DTC troubleshooting procedures. (See DTC TABLE ).
3		No	Go to the next step.
4	IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA Is DTC P0140 on FREEZE FRAME DATA?	Yes	Go to the next step.
4		No	Go to troubleshooting procedures for DTC on FREEZE FRAME DATA. (See DTC TABLE ).
5	VERIFY CURRENT INPUT SIGNAL STATUS Warm up engine. Access O2S12 for P0140 or O2S22 for P0160 PID using the WDS or equivalent. Verify PID while racing engine at least 10 times (in NEUTRAL (MTX) or PARK (ATX)). Is PID reading normal? More than 0.55 V at least once during engine racing.	Yes	Go to step 8.
5		No	Go to the next step.
6	INSPECT INSTALLATION OF REAR HO2S Check if rear HO2S is loosely installed. Is sensor installed securely?	Yes	Go to the next step.
6		No	Install sensor securely, then go to Step 10.
7	INSPECT GAS LEAKAGE FROM EXHAUST SYSTEM Visually check if any gas leakage is found between exhaust pipe and rear HO2S. Is there gas leakage?	Yes	Repair or replace any malfunctioning exhaust parts, then go to Step 10.
7		No	Inspect the following harnesses for open or short to ground circuit, repair or replace harness if necessary. Rear HO2S terminal A (wiring harness-side) to PCM terminal 2Q (wiring harness-side) Repair or replace harness if necessary. If all items above are normal, replace faulty sensor. Then go to Step 10.
8	INSPECT SEALING OF ENGINE COOLANT PASSAGE Perform "ENGINE COOLANT LEAKAGE INSPECTION." (See ENGINE COOLANT LEAKAGE INSPECTION [L3, AJ] ). Is there any malfunction?	Yes	Go to the next step.
8		No	Repair or replace the malfunctioning part according to inspection results. Then go to the Step 10.
9	INSPECT ENGINE COMPRESSION Inspect engine compression. (See COMPRESSION INSPECTION ). Is it normal?	Yes	Go to the next step.
9		No	Implement engine overhaul for repairs, then go to the next step.
10	VERIFY TROUBLESHOOTING OF DTC P0140 COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the WDS or equivalent. Turn the ignition switch off. Start engine and warm it up completely. Is PENDING CODE for this DTC present?	Yes	Replace PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION ).
10		No	Go to the next step.
11	VERIFY AFTER REPAIR PROCEDURE Perform the "After Repair Procedure". (See AFTER REPAIR PROCEDURE ). Is any DTC present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE ).
11		No	Troubleshooting completed.