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 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 TABLE [L5] .)
3		No	Go to the next step
4	IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA Is the DTC P2195 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	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] .) APP1 APP2 ECT MAF TPREL VSS Is there any signal that is far out of specification when the ignition switched to ON and the engine runs?	Yes	Repair or replace the malfunctioning parts according to the inspection results, then go to Step 15.
5		No	Go to the next step.
6	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 conditions (See PCM INSPECTION [L5] .) APP1 APP2 ECT MAF TPREL VSS Is there any signal which causes drastic changes?	Yes	Repair or replace the malfunctioning parts according to the inspection results, then go to Step 15
6		No	Go to the next step.
7	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.
7		No	Go to Step 9
8	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 15
8		No	Replace the A/F sensor, then go to Step 15 (See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [L5] .)
9	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 15.
9		No	Go to the next step.
10	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.
10		No	Replace the MAF/IAT sensor, then go to Step 15 (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [L5] .)
11	INSPECT FUEL LINE PRESSURE Inspect the fuel line pressure (See FUEL LINE PRESSURE INSPECTION [L5] .) Is there any malfunction	Yes	Fuel pressure is too high: Replace the fuel pump unit, then go to Step 15. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L5] .) Fuel pressure is low. Go to the next step.
11		No	Go to Step 14.
12	INSPECT FUEL LINE Visually inspect the fuel line from fuel pump to fuel infector for any leakage. Is there any leakage	Yes	Repair or replace the malfunctioning parts according to the inspection results, then go to Step 15
12		No	Go to the next step
13	INSPECT FUEL FILTER Visually inspect the fuel filter for foreign materials or stain Is there any malfunction	Yes	Repair or replace the malfunctioning parts according to the inspection results, then go to Step 15
13		No	Go to Step 15.
14	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 15.
14		No	Go to the next step
15	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] .)
15		No	Go to the next step.
16	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] .)
16		No	DTC troubleshooting completed