Diagnostic procedure

WARNING: This page is about a different car, the 2005 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

DTC P0012 [AJ] 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 FREEZE FRAME DATA on repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY Check for related Service Bulletins and/or online 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 CODE OR STORED DTCs Is DTC P2088 or P2089 present?	Yes	Go to appropriate DTC troubleshooting procedure. (See DTC TABLE .)
3		No	Go to the next step.
4	VERIFY ENGINE OIL PRESSURE Start engine. Does oil pressure warning light illuminate?	Yes	Inspect engine oil pressure. (See OIL PRESSURE INSPECTION .)
4		No	Go to the next step.
5	VERIFY TIMING CHAIN INSTALLATION Stop engine. Remove timing chain cover. Is camshaft timing mark at correct point? (See TIMING CHAIN REMOVAL/INSTALLATION .)	Yes	Go to the next step.
5		No	Reinstall timing chain, then go to Step 8. (See TIMING CHAIN REMOVAL/INSTALLATION .)
6	INSPECT OCV (RH) FOR MALFUNCTION Stop engine. Remove OCV (RH). (See OIL CONTROL VALVE (OCV) REMOVAL/INSTALLATION .) Inspect position of spool valve in OCV (RH). Is spool valve located at valve retard position?	Yes	VARIABLE VALVE TIMING MECHANISM IS NORMAL NOTE: This DTC is detected by intermittent concern. Intermittent concern might be removed by cleaning mode of variable valve timing control function. Go to the next step.
6		No	Replace OCV, then go to Step 8. (See OIL CONTROL VALVE (OCV) REMOVAL/INSTALLATION .)
7	INSPECT ENGINE OIL RUNNER Inspect the following engine oil runners for clogging or leakage: Between oil pressure switch and OCV (RH) Between OCV (RH) and variable valve timing actuator (RH) In variable valve timing actuator (RH) Is there any clogging or leakage?	Yes	Repair or replace suspected runner, then go to the next step.
7		No	VARIABLE VALVE TIMING MECHANISM IS NORMAL NOTE: This DTC is detected by intermittent concern. Intermittent concern might be removed by cleaning mode of variable valve timing control function. Go to the next step.
8	VERIFY TROUBLESHOOTING OF DTC P0012 COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the WDS or equivalent. Start engine and warm it up completely. Is same DTC present?	Yes	Replace PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION .)
8		No	Go to the next step.
9	VERIFY AFTER REPAIR PROCEDURE Perform "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE .) Are any DTCs present?	Yes	Go to applicable DTC troubleshooting. (See DTC TABLE .)
9		No	Troubleshooting completed.