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 HAS BEEN RECORDED Has FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
1		No	Record FREEZE FRAME DATA 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 Service Bulletins available?	Yes	Perform repair or diagnosis according to the available Service Bulletins. If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	VERIFY RELATED PENDING CODE OR STORED DTCs Switch the ignition to off, then to the ON (Engine off) Verify related pending code or stored DTCs. Are other DTCs present?	Yes	Go to the appropriate DTC troubleshooting. (See DTC TABLE [MZI-3.7] .)
3		No	Go to the next step.
4	VERIFY CURRENT INPUT SIGNAL STATUS (KEY TO ON/IDLE) Access APP1, APP2, ECT, IAT, MAF, RPM TP REL and VSS PIDs using the M-MDS (See PCM INSPECTION [MZI-3.7] .) Is there any signal that is far out of specification when the ignition is switched ON, and the engine is run at idle?	Yes	Inspect the suspected circuit or part or both according to inspection results. Then go to Step 17 (See PCM INSPECTION [MZI-3.7] .)
4		No	Go to the next step
5	VERIFY CURRENT INPUT SIGNAL STATUS UNDER TROUBLE CONDITION Inspect the same PIDs as in Step 4 when simulating the FREEZE FRAME DATA condition Is there any signal which causes drastic changes?	Yes	Inspect the suspected circuit or part or both according inspection results. Then go to Step 17 (See PCM INSPECTION [MZI-3.7] .)
5		No	Go to the next step.
6	INSPECT FOR EXCESSIVE AIR SUCTION IN INTAKE AIR SYSTEM Inspect for air leakage at the following. Between the dynamic chamber and the cylinder head Is there any malfunction?	Yes	Repair or replace the suspected part, then go to Step 17.
6		No	Go to the next step.
7	INSPECT SPARK PLUG CONDITION Switch the ignition to off. Remove the spark plug from the suspected cylinder. Check the spark plug condition. Cracks Excess wear Gap Wet Is any problem found on the spark plug?	Yes	If the spark plug is wet, fuel flooding is suspected. Go to Step 9. If the spark plug has a crack, excess wear or improper gap, replace the malfunctioning spark plug. Then go to Step 17 (See SPARK PLUG REMOVAL/INSTALLATION [MZI-3.7] .)
7		No	Go to the next step.
8	INSPECT IGNITION SYSTEM OPERATION FOR SUSPECTED CYLINDER Perform the spark test for the suspected cylinder. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZI-3.7] .) Are the results of the spark test normal?	Yes	Go to the next step.
8		No	Replace or replace the malfunctioning part according to the spark test results, then go to Step 17.
9	INSPECT FUEL INJECTOR WIRING HARNESS Remove the intake air system parts. Disconnect the fuel injector connector on the suspected cylinder Connect the noid light to the fuel injector connector terminals Verify the light dimness during cranking Does the noid light illuminate?	Yes	Go to the next step.
9		No	Inspect the fuel injector wiring harnesses. Repair or replace if necessary, then go to Step 17.
10	INSPECT FUEL INJECTOR OPERATION Remove fuel injector from the suspected cylinder (See FUEL INJECTOR REMOVAL/INSTALLATION [MZI-3.7] .) Swap the fuel injector with one from another cylinder Start the engine and run it at idle Is there the misfire DTC for the cylinder which has a suspected fuel injector?	Yes	Replace fuel injector, then go to Step 17 (See FUEL INJECTOR REMOVAL/INSTALLATION [MZI-3.7] .)
10		No	Go to the next step.
11	INSPECT FOR AIR SUCTION AT INTAKE AIR SYSTEM Inspect for air leakage at the following Around the connection of the dynamic chamber and the intake manifold Around the connection of the intake manifold and the cylinder head Is air leakage found?	Yes	Repair or replace the suspected part, then go to Step 17.
11		No	Go to the next step.
12	INSPECT OPERATION OF PURGE SOLENOID VALVE Inspect the purge control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZI-3.7] .) Does the purge control system work correctly?	Yes	Go to the next step.
12		No	Repair or replace the malfunctioning part according to the purge control system inspection results, then go to Step 17.
13	INSPECT FUEL LINE PRESSURE Switch the ignition to off. Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [MZI-3.7] .) Is there any malfunction?	Yes	If the fuel line pressure is too low, go to the next step If the fuel line pressure is excessively high, check as follows. Fuel pump maximum pressure Fuel return line for clogging If all of the above are normal, replace the pressure regulator. (See FUEL PUMP UNIT DISASSEMBLY/ASSEMBLY [MZI-3.7] .) Then go to Step 17
13		No	Go to Step 15.
14	INSPECT FUEL LINE FROM FUEL PUMP TO FUEL DELIVERY PIPE Visually inspect the fuel line for any leakage. Is any fuel leakage found?	Yes	Replace suspected fuel line, then go to Step 17.
14		No	Inspect the low-pressure side fuel filter for the following: Foreign material or staining inside the fuel filter Perform the following actions as a result: If foreign material or staining is found inside the fuel filter (low-pressure side), clean the fuel tank and filter If normal, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZI-3.7] .) Then go to Step 17
15	INSPECT SEALING OF ENGINE COOLANT PASSAGE WARNING: Never remove the cooling system cap or loosen the radiator drain plug while the engine is running, or when the engine and radiator are hot. Scalding engine coolant and steam may shoot out and cause serious injury. It may also damage the engine and cooling system. Turn off the engine and wait until it is cool. Even then, be very careful when removing the cap. Wrap a thick cloth around it and slowly turn it counterclockwise to the first stop. Step back while the pressure escapes. When you are sure all the pressure is gone, press down on the cap using the cloth, turn it, and remove it. Remove the radiator cap. Implement the procedure to bleed air from the engine coolant, then run the engine at idle. Are there any small bubbles which make the engine coolant white at filling opening? NOTE: Large bubbles are normal since they are remaining air coming from the engine coolant passage.	Yes	Air penetrates due to poor sealing of the head gasket or other areas between the combustion chamber and the engine coolant passage. Repair or replace malfunctioning parts, then go to Step 17.
15		No	Go to the next step
16	INSPECT ENGINE COMPRESSION Inspect the engine compression. (See COMPRESSION INSPECTION [MZI-3.7] .) Is the engine compression normal?	Yes	Go to the next step. (The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.)
16		No	Overhaul the engine, then go to the next step.
17	VERIFY TROUBLESHOOTING OF MISFIRE DTC HAS BEEN COMPLETED Verify that all disconnected connectors are reconnected. Switch the ignition to ON (Engine off) Clear the DTC from the PCM memory using the M-MDS. Perform the OBD-II Drive Mode up to "Misfire and Fuel Monitors" (Step 11) (See OBD-II DRIVE MODE [MZI-3.7] ) Retrieve DTCs using the M-MDS Is the PENDING CODE for this DTC present?	Yes	Replace the PCM, then go to the next step (See PCM REMOVAL/INSTALLATION [MZI-3.7] .)
17		No	Go to the next step
18	VERIFY AFTER REPAIR PROCEDURE Perform the "AFTER REPAIR PROCEDURE" (See AFTER REPAIR PROCEDURE [MZI-3.7] ) Are any DTC present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [MZI-3.7] .)
18		No	Troubleshooting completed