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Engine Controls - MIL ON/DTC P0401 Set



Bulletin No: 01-004/08

Last Issued: 02/07/2008


2007-2008 Mazda3 vehicles (except CA 2.0/2.3L) with VINs lower than JM1BK**** ** 861723 (produced before November 27, 2007)

2008 Mazda5 vehicles with VINs lower than JM1CR**** ** 303918 (produced before November 12, 2007)

2008 Mazda6 vehicles (2.3L except CA A/T) produced before December 3, 2007


Some vehicles may experience an MIL turning ON with DTC P0401 (EGR flow insufficient) without any problems on a related part. This is due to inadequate PCM calibration.

To fix the problem, the PCM software has been changed. Customers having this concern should have their vehicle repaired using the following repair procedure.


1. Reboot the IDS to clear memory before reprogramming.

2. Using IDS 52.3 or later software, reprogram the PCM to the latest calibration (refer to "Calibration Information" table shown at the end of this bulletin) by following the "Module Reprogramming" procedure.

NOTE: ^ Always update the IDS tool first, then follow on-screen instructions to download the needed calibration file for PCM reprogramming.

^ It is not necessary to remove any fuses or relays during PCM reprogramming when the IDS screen prompts you to do so. You may accidentally stop power to one of the PCM terminals and cause the PCM to be blanked, or you may receive error messages during the IDS reprogramming procedure.

^ IDS shows the calibration part numbers after programming the PCM.

^ Please be aware that PCM calibration part numbers and file names listed in any Service Bulletin may change due to future releases of IDS software, and additional revisions made to those calibrations for service related concerns.

^ When reprogramming a PCM, IDS will always display the "latest" calibration P/N available for that vehicle. If any calibration has been revised/updated to contain new information for a new service concern/issue, it will also contain all previously released calibrations.

^ When performing this procedure, we recommend that a battery charger be installed on the vehicle battery and turned ON to a maximum charge of no more than 20 AMPS to keep the vehicle battery up to capacity. If you exceed 20 AMPS, it could damage the VCM.

3. After performing the PCM reprogramming procedure, verify the repair by starting the engine and making sure there are no MIL illumination or abnormal warning lights present.

NOTE: ^ If any DTCs should remain after performing DTC erase, diagnose the DTCs according to the appropriate Troubleshooting section of the Workshop Manual.

^ After PCM reprogramming, it is no longer necessary to road test the vehicle to relearn" KAM (Keep Alive Memory).

4. Fill out an "Authorized Modifications" label (P/N 9999-95-AMDC-97) with the new PCM calibration information, your dealer code, and today's date.

5. Place the "Authorized Modifications" label on the "A" pillar below the tear tag in the driver doorjamb.