Diagnostic procedure

WARNING: This page is about a different car, the 2005 Mazda RX-8. However, it is still accessible from the selected car via links, so may be relevant.

DTC P0125 DIAGNOSTIC PROCEDURE

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 the 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 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 CURRENT INPUT SIGNAL STATUS: IS CONCERN INTERMITTENT OR CONSTANT? Connect the WDS or equivalent to the DLC-2. Start the engine and warm it up completely. Access the ECT PID. Is the ECT PID more than 70 °C {158 °F} ?	Yes	Intermittent concern exists. Perform the "INTERMITTENT CONCERNS TROUBLESHOOTING". (See INTERMITTENT CONCERN TROUBLESHOOTING .)
3		No	Go to the next step.
4	INSPECT ECT SENSOR Inspect the ECT sensor. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION .) Is there any malfunction?	Yes	Replace the ECT sensor, then go to Step 6. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION .)
4		No	Go to the next step.
5	INSPECT MAF SENSOR Inspect the MAF sensor. (See MASS AIR FLOW (MAF) SENSOR INSPECTION .) Is there any malfunction?	Yes	Replace the MAF/IAT sensor, then go to the next step. (See MASS AIR FLOW (MAF)/INTAKE AIR TEMPERATURE (IAT) SENSOR REMOVAL/INSTALLATION .)
5		No	Go to the next step.
6	VERIFY TROUBLESHOOTING OF DTC P0125 COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the WDS or equivalent. Access the ECT PID. Wait until the ECT PID less than 20 °C {68 °F}. Start the engine and warm it up completely. Is the PENDING CODE same as the DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION .)
6		No	Go to the next step.
7	VERIFY AFTER REPAIR PROCEDURE Perform the "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE .) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE .)
7		No	DTC troubleshooting completed.