BULLETIN NOTES
This bulletin supersedes the previously issued buletin(s) listed below: The changes are noted in Red.
Previous TSBs:

Date(s) Issued:

01-001/21

01/14/21

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)
2016-2021 CX-9 (US spec) with SKYACTIV-G 2.5T with VINS lower than JM3TC******519519 (produced before January
26, 2021)
2016-2021 CX-9 (Mexico spec) with SKYACTIV-G 2.5T with VINS lower than JM3TC******454021 (produced before
January 29, 2021)

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 position of the EGR valve is learned improperly as it is not equipped with a position sensor.
3. While idling, the EGR gas improperly mixes with 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 (for service) 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.

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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 122.05 or later software. Refer to
IDS Reprogramming Procedure.
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
Model

Year

Drive

File Name

Mazda6

2018 (US)
2019 (Mexico)

-

PYH7-188K2-E

CX-9

2016-2017 (US and Mexico)

2WD

PYFL-188K2-R

4WD

PYFM-188K2-R

CX-9

2018 (US and Mexico)

2WD

PYD7-188K2-F

4WD

PYD8-188K2-F

CX-9

2019 (US)

2WD

PX23-188K2-D

4WD

PX24-188K2-D

CX-9

2020-2021 (US)

2WD

PXM3-188K2-D

4WD

PXM4-188K2-D

CX-9

2019 (Mexico)

2WD

PXB3-188K2-D

CX-9

2020-2021 (Mexico)

4WD

PXB4-188K2-D

2WD

PXM8-188K2-C

4WD

PXM9-188K2-C

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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

Valve, EGR

1

Only if EGR valve needs to be replaced.

NOTE: No part is required for PCM reprogramming.
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

Operation Number / Labor Hours:

0
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.

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