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 P2177.00 or P2187.00 also present?	Yes	Go to the applicable DTC inspection. (See DTC P2177:00 [L5] .) (See DTC P2187:00 [L5] .)
3		No	Go to the next step.
4	IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA Is the DTC P2096.00 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 20.
6		No	Replace the HO2S, then go to Step 20. (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 20. (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 TP REL 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 20.
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 TP REL 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 20.
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 20
11		No	Replace the A/F sensor, then go to Step 20 (See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [L5] .)
12	VERIFY CURRENT INPUT SIGNAL STATUS OF MAF SENSOR Connect the M-MDS to the DLC-2. Start the engine Access the MAF PID using the M-MDS. Verify that the MAF PID changes quickly according to engine speed. Is the PID normal?	Yes	Go to the next step.
12		No	Replace the MAF/IAT sensor, then go to Step 20. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [L5] .)
13	INSPECT INTAKE AIR SYSTEM FOR EXCESSIVE AIR SUCTION Visually inspect the hose in intake air system for looseness, cracks or damages Is there any malfunction?	Yes	Repair or replace the malfunctioning parts according to the inspection results, then go to Step 20.
13		No	Go to the next step
14	INSPECT FUEL LINE PRESSURE Perform the "FUEL LINE PRESSURE INSPECTION" (See FUEL LINE PRESSURE INSPECTION [L5] .) Is there any malfunction?	Yes	Go to the next step
14		No	Go to Step 16.
15	INSPECT FUEL SYSTEM FOR FUEL LEAKAGE Visually inspect the fuel leakage in the fuel system Is there any leakage?	Yes	Repair or replace the malfunctioning parts according to the inspection results, then go to Step 20
15		No	Replace the fuel pump unit, then go to Step 20 (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L5] .)
16	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 18.
16		No	Go to the next step
17	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 20
17		No	Repair or replace the malfunctioning parts according to the inspection results, then go to Step 20.
18	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 20
18		No	Go to the next step
19	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
19		No	Go to the next step
20	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] .)
20		No	Go to the next step
21	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] .)
21		No	DTC troubleshooting completed.