Diagnostic procedure

WARNING: This page is about a different car, the 2009 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

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 (A/F sensor, HO2S related) been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on 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 AND STORED DTC Switch the ignition to off, then to ON (engine off) Verify pending and stored DTCs using the M-MDS. Is the DTC P0443:00 also present?	Yes	Go to the applicable DTC inspection (See DTC P0443:00 [L5] .)
3		No	Go to the next step.
4	IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA Is the DTC P0139:00 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 [L5] .)
5	INSPECT INSTALLATION OF HO2S Inspect if the HO2S is loosely installed Is the HO2S installed securely?	Yes	Go to the next step
5		No	Retighten the HO2S, then go to Step 17.
6	INSPECT GAS LEAKAGE FROM EXHAUST SYSTEM Visually inspect if there is any gas leakage is found between the exhaust manifold and HO2S Is there gas leakage?	Yes	Repair or replace the malfunctioning part according to the inspection result, then go to Step 17.
6		No	Go to the next step.
7	INSPECT HO2S Inspect the HO2S. (See HEATED OXYGEN SENSOR (HO2S) INSPECTION [L5] .) Is there any malfunction?	Yes	Replace the HO2S, then go to Step 17 (See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [L5] .)
7		No	Go to the next step.
8	INSPECT LONG TERM FUEL TRIM Access the LONGFT1 PID using the M-MDS. Compare the PID with FREEZE FRAME DATA recorded at Step 1 Is it below FREEZE FRAME DATA value?	Yes	Engine is driven under rich condition Go to the next step.
8		No	Engine is driven under lean condition Go to Step 11
9	INSPECT FUEL LINE PRESSURE (EXCESSIVE FUEL LINE PRESSURE) Switch the ignition to off Inspect fuel line pressure while the engine running (See FUEL LINE PRESSURE INSPECTION [L5] .) Is there any malfunction?	Yes	Go to the next step.
9		No	Go to Step 14
10	INSPECT FUEL PUMP Inspect the fuel pump maximum pressure and fuel return pipe for clogging (See FUEL PUMP UNIT INSPECTION [L5] .) Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection result, then go to Step 17
10		No	Replace the fuel pump unit, then go to Step 17 (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L5] .)
11	INSPECT FUEL LINE PRESSURE (LOW FUEL LINE PRESSURE) Switch the ignition to off? Inspect fuel line pressure while the engine running (See FUEL LINE PRESSURE INSPECTION [L5] .) Is there any malfunction?	Yes	Go to the next step
11		No	Go to Step 14.
12	INSPECT FUEL LINE LEAKAGE Visually inspect the leakage from the fuel pump to fuel distributor Is there any leakage?	Yes	Repair or replace the malfunctioning part according to the inspection result, then go to Step 17.
12		No	Go to the next step
13	INSPECT FUEL FILTER Visually inspect the foreign materials or stain inside fuel filter (low-pressure side) Is there any foreign material or stain?	Yes	Repair or replace the malfunctioning part according to the inspection result, then go to Step 17.
13		No	Replace the fuel pump unit, then go to Step 17 (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L5] .)
14	INSPECT PURGE SOLENOID VALVE Inspect the purge solenoid valve (See PURGE SOLENOID VALVE INSPECTION [L5] .) Is there any malfunction?	Yes	Replace the purge solenoid valve, then go to Step 17. (See PURGE SOLENOID VALVE REMOVAL/INSTALLATION [L5] .)
14		No	Go to the next step.
15	INSPECT SEALING OF ENGINE COOLANT PASSAGE Perform the "ENGINE COOLANT LEAKAGE INSPECTION". (See ENGINE COOLANT LEAKAGE INSPECTION [L5] .) Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection result, then go to Step 17.
15		No	Go to the next step.
16	INSPECT ENGINE COMPRESSION Inspect the engine compression. (See COMPRESSION INSPECTION [L5] .) Is there any malfunction?	Yes	Perform the engine overhaul for repairs, then go to the next step.
16		No	Go to the next step.
17	VERIFY DTC TROUBLESHOOTING COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the M-MDS. Perform the DRIVE Mode 03 (A/F sensor heater, HO2S heater, A/F sensor, HO2S and TWC Repair Verification Drive Mode). (See OBD-II DRIVE MODE [L5] .) Is the PENDING CODE for this DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [L5] .)
17		No	Go to the next step.
18	VERIFY AFTER REPAIR PROCEDURE Perform the "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE [L5] .) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [L5] .)
18		No	DTC troubleshooting completed.