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 P2401 [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 Turn ignition switch to OFF, then ON (Engine off). Verify related pending code or stored DTCs. Is DTC P2405 present?	Yes	Go to appropriate DTC inspection. (See DTC P2405 .)
3		No	Go to the next step.
4	INSPECT EVAP SYSTEM LEAK DETECTION PUMP CONNECTOR FOR POOR CONNECTION Turn the ignition switch off. Disconnect the EVAP system leak detection pump connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). Is there any malfunction?	Yes	Repair or replace the terminal, then go to Step 10.
4		No	Go to the next step.
5	INSPECT EVAP SYSTEM LEAK DETECTION PUMP POWER CIRCUIT FOR OPEN CIRCUIT Turn the ignition switch off. Disconnect main relay. Disconnect EVAP system leak detection pump connector. Check continuity between EVAP system leak detection pump terminal A (harness-side) and main relay terminal C (harness-side). Is there continuity?	Yes	Repair or replace harness for open circuit, then go to Step 10.
5		No	Go to the next step.
6	INSPECT EVAP SYSTEM LEAK DETECTION PUMP SIGNAL CIRCUIT FOR SHORT TO GND Turn the ignition switch off. Disconnect EVAP system leak detection pump connector. Check continuity between EVAP system leak detection pump terminal D (harness-side) and body GND. Is there continuity?	Yes	Repair or replace harness for short to GND, then go to Step 10.
6		No	Go to the next step.
7	INSPECT EVAP SYSTEM LEAK DETECTION PUMP Inspect EVAP system leak detection pump. (See EVAPORATIVE EMISSION (EVAP) SYSTEM LEAK DETECTION PUMP INSPECTION .) Is there any malfunction?	Yes	Replace EVAP system leak detection pump, then go to Step 10. (See EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM COMPONENT REMOVAL/INSTALLATION .)
7		No	Go to the next step.
8	INSPECT PCM CONNECTOR FOR POOR CONNECTION Turn the ignition switch off. Disconnect PCM connector. Check for poor connection (such as damaged, pulled-out pins, and corrosion). Is there any malfunction?	Yes	Repair or replace the terminal, then go to Step 10.
8		No	Go to the next step.
9	INSPECT EVAP SYSTEM LEAK DETECTION PUMP SIGNAL CIRCUIT FOR OPEN CIRCUIT Turn the ignition switch off. Disconnect EVAP system leak detection pump connector. Check continuity between EVAP system leak detection pump terminal D (harness-side) and PCM terminal 94 (harness-side) Is there continuity?	Yes	Go to the next step.
9		No	Repair or replace harness for open circuit, then go to Step 10.
10	VERIFY TROUBLESHOOTING OF DTC P2401 COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the WDS or equivalent. Perform EVAP system test using the WDS or equivalent. (See EVAPORATIVE EMISSION (EVAP) SYSTEM LEAK INSPECTION .) Is the same DTC present? NOTE: If EVAP system test function is not available, take following procedure. Start engine and perform "EVAP system Repair Verification Drive Mode". (See OBD-II DRIVE MODE .) Is PENDING CODE same as DTC present?	Yes	Replace PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION .)
10		No	Go to the next step.
11	VERIFY AFTER REPAIR PROCEDURE Perform "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE .) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE .)
11		No	Troubleshooting completed.