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 (fuel system 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 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 P2178:00 or P2188:00 also present?	Yes	Go to the applicable DTC inspection. (See DTC P2178:00 [L5] .) (See DTC P2188:00 [L5] .)
3		No	Go to the next step.
4	IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA Is the DTC P2097:00 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 HO2S Inspect the HO2S. (See HEATED OXYGEN SENSOR (HO2S) INSPECTION [L5] .) Is there any malfunction?	Yes	Go to the next step.
5		No	Go to Step 7.
6	INSPECT EXHAUST GAS LEAKAGE Visually inspect for the exhaust gas leakage between the TWC and HO2S Is there any leakage?	Yes	Repair or replace the malfunctioning parts according to the inspection results, then go to Step 19.
6		No	Replace the HO2S, then go to Step 19. (See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [L5] .)
7	INSPECT IAT SENSOR Inspect the IAT sensor (See INTAKE AIR TEMPERATURE (IAT) SENSOR INSPECTION [L5] .) Is there any malfunction?	Yes	Replace the IAT sensor, then go to Step 19 (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [L5] .)
7		No	Go to the next step.
8	VERIFY CURRENT INPUT SIGNAL STATUS Connect the M-MDS to the DLC-2 Access the following PIDs using the M-MDS (See PCM INSPECTION [L5] .) ECT MAF TPREL VSS Are the PIDs normal?	Yes	Go to the next step.
8		No	Repair or replace the malfunctioning parts according to the inspection results, then go to Step 19.
9	VERIFY CURRENT INPUT SIGNAL STATUS UNDER FREEZE FRAME DATA CONDITION Connect the M-MDS to the DLC-2 Access the following PIDs using the M-MDS under the FREEZE FRAME DATA condition (See PCM INSPECTION [L5] .) ECT MAF TPREL VSS Are the PIDs normal?	Yes	Go to the next step
9		No	Repair or replace the malfunctioning parts according to the inspection results, then go to Step 19.
10	INSPECT A/F SENSOR Inspect the A/F sensor (See AIR FUEL RATIO (A/F) SENSOR INSPECTION [L5] .) Is there any malfunction?	Yes	Go to the next step.
10		No	Go to Step 12.
11	INSPECT EXHAUST GAS LEAKAGE Visually inspect for the exhaust gas leakage between the exhaust manifold and A/F sensor. Is there any leakage?	Yes	Repair or replace the malfunctioning parts according to the inspection results, then go to Step 19.
11		No	Replace the A/F sensor, then go to Step 19. (See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [L5] .)
12	INSPECT FUEL LINE PRESSURE Perform the "FUEL LINE PRESSURE INSPECTION". (See FUEL LINE PRESSURE INSPECTION [L5] .) Is there any malfunction?	Yes	Replace the fuel pump unit, then go to Step 19. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L5] .)
12		No	Go to the next step.
13	INSPECT LONG TERM FUEL TRIM Connect the M-MDS to the DLC-2 Access the LONGFT1 PID using the M-MDS Compare the LONGFT1 PID with recorded FREEZE FRAME DATA at Step 1 Is the LONGFT1 PID above FREEZE FRAME DATA?	Yes	Go to the next step
13		No	Go to Step 15.
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 15. (See PURGE SOLENOID VALVE REMOVAL/INSTALLATION [L5] .)
14		No	Go to the next step
15	INSPECT IGNITION SYSTEM OPERATION Perform the spark test (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [L5] .) Is strong blue spark visible at each cylinder?	Yes	Go to Step 17.
15		No	Go to the next step
16	INSPECT IGNITION COIL RELATED WIRING HARNESS Inspect the ignition coil related wiring harness condition (intermittent open or short) for all cylinders. Is there any malfunction?	Yes	Repair or replace the malfunctioning wiring harness, then go to Step 19.
16		No	Repair or replace the malfunctioning parts according to the inspection results, then go to Step 19
17	INSPECT FUEL INJECTOR OPERATION Inspect the fuel injector operation (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [L5] .) Is there any malfunction?	Yes	Repair or replace the malfunctioning parts according to the inspection results, then go to Step 19
17		No	Go to the next step.
18	INSPECT ENGINE COMPRESSION Inspect the engine compression. (See COMPRESSION INSPECTION [L5] .) Is there any malfunction?	Yes	Overhaul the engine for repair, then go to the next step.
18		No	Go to the next step.
19	VERIFY DTC TROUBLESHOOTING COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the M-MDS. Perform the PCM Adaptive Memory Produce 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] .)
19		No	Go to the next step.
20	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] .)
20		No	DTC troubleshooting completed.