01-001-21-3761

Technical
Service Bulletin
Mazda North American Operations
Irvine, CA 92618-2922
Subject:
ROUGH IDLE DUE TO EGR VALVE NOT CLOSING
Bulletin No.: 01-001/21
Last Issued: 01/14/2021
APPLICABLE MODEL(S)/VINS
2018 Mazda6 (US spec) with SKYACTIV-G 2.5T with VINS lower than JM1GL******336737 (produced
before December 22, 2018)
2019 Mazda6 (Mexico spec) with SKYACTIV-G 2.5T with VINS lower than JM1GL******336562 (produced
before December 22, 2018)
2018 CX-9 with SKYACTIV-G 2.5T with VINS lower than JM3TC******237358 (produced before July 1,
2018)
DESCRIPTION
Some vehicles may exhibit an occasional rough idle accompanied with DTC P0300:00 (Random misfire)
due to the following:
1. While closing the EGR valve, carbon deposit etc. pinched at the valve seat prevents the valve from
closing completely.
2. The closed positon of the EGR valve is learned improperly as it is not equipped with a position sensor.
3. While idling, the EGR gas improperly mixes in fresh air through the EGR valve that is not closed properly.
4. Misfire occurs.
To eliminate this concern, the control software of the PCM has been modified to force the learning of the
closed position of the EGR valve when a misfire is detected at idle.
Customers having this concern should have their vehicle repaired using the following repair procedure.
REPAIR PROCEDURE
1. Verify customer concern.


If the concern continues even after cycling the engine off and on, check the EGR valve and clean
the carbon deposit if it prevents the valve from closing.
If damage is found on the valve seat in the EGR valve, replace the EGR valve.
2. Reprogram the PCM with Mazda Modular Diagnostic System (M-MDS) using IDS 120.03 or later
software. Refer to IDS Reprogramming Procedure.
Page 1 of 3
CONSUMER NOTICE: The information and instructions in this bulletin are intended for use by skilled technicians. Mazda technicians utilize the proper tools/
equipment and take training to correctly and safely maintain Mazda vehicles. These instructions should not be performed by “do-it-yourselfers.” Customers
should not assume this bulletin applies to their vehicle or that their vehicle will develop the described concern. To determine if the information applies,
customers should contact their nearest authorized Mazda dealership. Mazda North American Operations reserves the right to alter the specifications and
contents of this bulletin without obligation or advance notice. All rights reserved. No part of this bulletin may be reproduced in any form or by any means,
electronic or mechanical---including photocopying and recording and the use of any kind of information storage and retrieval system ---without permission in
writing.
© 2021 Mazda North American Operations, U.S.A.
01/20/2021 9:07 AM tlawrenc
Bulletin No.: 01-001/21
Last Issued: 01/14/2021
3. Verify the repair by starting the engine and making sure there is no rough idle, CHECK ENGINE light ON
or abnormal warning lights present.
NOTE: If any DTCs should remain after performing DTC erase, diagnose the DTCs according to the
appropriate troubleshooting on MGSS.
CALIBRATION INFORMATION
Model Drive
Mazda6
CX-9
-
File Name
PYH7-188K2-E
2WD PYD7-188K2-F
4WD PYD8-188K2-F
PARTS INFORMATION
Parts Number
Description
Qty.
Notes
PY8V-20-305 Gasket, EGR Valve
1
Only if EGR valve needs to be cleaned or replaced.
PY8V-20-300
1
Only if EGR valve needs to be replaced.
Valve, EGR
NOTE: No part is required for PCM reprogramming.
Page 2 of 3
CONSUMER NOTICE: The information and instructions in this bulletin are intended for use by skilled technicians. Mazda technicians utilize the proper tools/
equipment and take training to correctly and safely maintain Mazda vehicles. These instructions should not be performed by “do-it-yourselfers.” Customers
should not assume this bulletin applies to their vehicle or that their vehicle will develop the described concern. To determine if the information applies,
customers should contact their nearest authorized Mazda dealership. Mazda North American Operations reserves the right to alter the specifications and
contents of this bulletin without obligation or advance notice. All rights reserved. No part of this bulletin may be reproduced in any form or by any means,
electronic or mechanical---including photocopying and recording and the use of any kind of information storage and retrieval system ---without permission in
writing.
© 2021 Mazda North American Operations, U.S.A.
01/20/2021 9:07 AM tlawrenc
Bulletin No.: 01-001/21
Last Issued: 01/14/2021
WARRANTY INFORMATION
NOTE:



This warranty information applies only to verified customer complaints on vehicles eligible for
warranty repair.
This repair will be covered under Federal Emission Warranty.
Additional diagnostic time cannot be claimed for this repair.
Warranty Type
A
Symptom Code
03
Damage Code
9W
Part Number Main Cause
5555-18-881
Quantity
0
Operation Number / Labor Hours:
XXS91AFX / 0.3 Hrs. (PCM reprogramming only)
XXS91BFX / 0.6 Hrs. (PCM reprogramming and
checking/cleaning EGR valve)
XXS91CFX / 0.6 Hrs. (PCM reprogramming and
checking/cleaning/replacing EGR valve)
NOTE: If the EGR valve is cleaned and/or replaced, claim the parts as related parts.
Page 3 of 3
CONSUMER NOTICE: The information and instructions in this bulletin are intended for use by skilled technicians. Mazda technicians utilize the proper tools/
equipment and take training to correctly and safely maintain Mazda vehicles. These instructions should not be performed by “do-it-yourselfers.” Customers
should not assume this bulletin applies to their vehicle or that their vehicle will develop the described concern. To determine if the information applies,
customers should contact their nearest authorized Mazda dealership. Mazda North American Operations reserves the right to alter the specifications and
contents of this bulletin without obligation or advance notice. All rights reserved. No part of this bulletin may be reproduced in any form or by any means,
electronic or mechanical---including photocopying and recording and the use of any kind of information storage and retrieval system ---without permission in
writing.
© 2021 Mazda North American Operations, U.S.A.
01/20/2021 9:07 AM tlawrenc