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 heater, HO2S heater 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	INSPECT HO2S CONNECTOR CONDITION Switch the ignition to off Disconnect the HO2S connector Inspect for poor connection (such as damaged/pulled-out pins, corrosion) Is there any malfunction?	Yes	Repair or replace the terminal and/or connector, then go to Step 9.
3		No	Go to the next step.
4	INSPECT HO2S HEATER POWER SUPPLY CIRCUIT FOR SHORT TO GROUND OR OPEN CIRCUIT Switch the ignition to ON (engine off) Measure the voltage between HO2S terminal C (wiring harness-side) and body ground. Is the voltage B+ ?	Yes	Go to the next step.
4		No	Repair or replace the wiring harness for a possible short to ground or open circuit, then go to Step 9.
5	INSPECT HO2S HEATER Inspect the HO2S heater (See HEATED OXYGEN SENSOR (HO2S) INSPECTION [L5] .) Is there any malfunction?	Yes	Replace the HO2S, then go to Step 9. (See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [L5] .)
5		No	Go to the next step.
6	INSPECT PCM CONNECTOR CONDITION Switch the ignition to off. Disconnect the PCM connector. Inspect for poor connection (such as damaged/pulled-out pins, corrosion) Is there any malfunction?	Yes	Repair or replace the terminal and/or connector, then go to Step 9.
6		No	Go to the next step.
7	INSPECT HO2S HEATER CONTROL CIRCUIT FOR SHORT TO GROUND Inspect for continuity between HO2S terminal D (wiring harness-side) and body ground. Is there continuity?	Yes	Repair or replace the wiring harness for a possible short to ground, then go to Step 9.
7		No	Go to the next step
8	INSPECT HO2S CONTROL CIRCUIT FOR OPEN CIRCUIT Inspect for continuity between HO2S terminal D (wiring harness-side) and PCM terminal 2B (wiring harness-side) Is there continuity?	Yes	Go to the next step.
8		No	Repair or replace the wiring harness for a possible open circuit, then go to the next step
9	VERIFY DTC TROUBLESHOOTING COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the M-MDS Perform the KOEO/KOER self test (See KOEO/KOER SELF TEST [L5] .) Is the PENDING CODE for this DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [L5] .)
9		No	Go to the next step.
10	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] .)
10		No	DTC troubleshooting completed.