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	INSPECT FOR MISFIRE CONCERNS AND AFTERMARKET EQUIPMENT Switch the ignition to off. Verify for the following: Misfire concern Non-factory or aftermarket equipment that may increase the exhaust temperature Disconnect the A/F sensor connector. Inspect the A/F sensor connector for damage or corrosion. Is there any concern present?	Yes	Repair suspect part, if necessary. Go to Step 6.
3		No	Go to the next step.
4	INSPECT A/F SENSOR HEATER CIRCUIT FOR SHORT CIRCUIT TO POWER SUPPLY Disconnect the PCM connector Switch the ignition to ON (Engine off) Measure the voltage between A/F sensor wiring harness-side connector terminal 4 and ground Is any voltage present?	Yes	Repair for a short to the power supply, then go to Step 6.
4		No	Go to the next step.
5	INSPECT A/F SENSOR CIRCUITS FOR OPEN CIRCUIT IN WIRING HARNESS Switch the ignition to off. Measure the resistance of the following on the harness-side connector. For P0030:00: A/F sensor (RH) terminal 5 and PCM terminal 2AC A/F sensor (RH) terminal 3 and PCM terminal 2AG A/F sensor (RH) terminal 4 and PCM terminal 2J For P0050:00: A/F sensor (LH) terminal 5 and PCM terminal 2AE A/F sensor (LH) terminal 3 and PCM terminal 2AK A/F sensor (LH) terminal 4 and PCM terminal 2E Is the resistance less than 5 ohms?	Yes	Repair for an open circuit (See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [MZI-3.7] .) Go to the next step.
5		No	Repair for an open circuit. Go to the next step.
6	VERIFY TROUBLESHOOTING OF DTC P0030:00, P0050:00 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 KOER self-test. (See KOEO/KOER SELF TEST [MZI-3.7] .) 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] .)
6		No	Go to the next step.
7	VERIFY AFTER REPAIR PROCEDURE Perform "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE [MZI-3.7] .) Are any DTC displayed?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [MZI-3.7] .)
7		No	Troubleshooting completed.