Diagnostic procedure

DTC P0131 [L3] DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA (MODE 2) Is DTC P0131 on FREEZE FRAME DATA (Mode 2)?	Yes	Go to the next step.
1		No	Go to troubleshooting for DTC on FREEZE FRAME DATA (Mode 2). (See DTC TABLE .)
2	VERIFY FREEZE FRAME DATA (MODE 12) AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED Have FREEZE FRAME DATA (Mode 12) and DIAGNOSTIC MONITORING TEST RESULTS (A/F sensor, HO2S related) been recorded?	Yes	Go to the next step.
2		No	Record the FREEZE FRAME DATA (Mode 12) and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.
3	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.
3		No	Go to the next step.
4	VERIFY RELATED PENDING OR STORED DTC Turn the ignition switch off, then to the ON position (Engine off). Verify the pending code or stored DTCs using the M-MDS. Is other DTC present?	Yes	Go to the appropriate DTC troubleshooting procedures. (See DTC TABLE .)
4		No	Go to the next step.
5	INSPECT A/F SENSOR CONNECTOR FOR POOR CONNECTION Turn the ignition switch off. Disconnect the A/F sensor connector. Inspect for poor connection (such as damaged/pulled-out pins, corrosion). Is there any malfunction?	Yes	Repair or replace the terminal, then go to Step 10.
5		No	Go to the next step.
6	INSPECT A/F SENSOR CIRCUIT FOR SHORT TO GROUND A/F sensor connector is disconnected. Turn the ignition switch off. Inspect for continuity between the following terminals and body ground: A/F sensor terminal B (wiring-harness-side) and body ground A/F sensor terminal D (wiring-harness-side) and body ground A/F sensor terminal F (wiring-harness-side) and body ground Is there continuity?	Yes	If the short to ground circuit could be detected: Repair or replace for a possible short to ground. If the short to ground circuit could not be detected: Replace the PCM (short to ground in PCM internal circuit). (See PCM REMOVAL/INSTALLATION .) Then go to Step 10.
6		No	Go to the next step.
7	INSPECT PCM CONNECTOR FOR POOR CONNECTION Turn the ignition switch off. Disconnect the PCM connector. Inspect for poor connection (such as damaged/pulled-out pins, corrosion). Is there any malfunction?	Yes	Repair or replace the terminal, then go to Step 10. (
7		No	Go to the next step.
8	INSPECT A/F SENSOR CIRCUIT FOR OPEN CIRCUIT A/F sensor and PCM connectors are disconnected. Turn the ignition switch off. Inspect for continuity between the following circuits: A/F sensor terminal B (wiring-harness-side) and PCM terminal 2AD (wiring-harness-side) A/F sensor terminal D (wiring-harness-side) and PCM terminal 2AC (wiring-harness-side) A/F sensor terminal F (wiring-harness-side) and PCM terminal 2Z (wiring-harness-side) Is there continuity?	Yes	Go to the next step.
8		No	Repair or replace the wiring harness for a possible open circuit, then go to Step 10.
9	INSPECT A/F SENSOR Inspect the A/F sensor. (See AIR FUEL RATIO (A/F) SENSOR INSPECTION .) Is there any malfunction?	Yes	Replace the A/F sensor, then go to Step 10. (See AIR FUEL RATIO (A/F) SENSOR, HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION .)
9		No	Go to the next step.
10	VERIFY TROUBLESHOOTING OF DTC P0131 COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the M-MDS. Perform the KOER self-test with M-MDS, or 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	Replace the 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 .) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE .)
11		No	DTC troubleshooting completed.