NHTSA ID Number: 10190956
Manufacturer Communication Number: 01-011-21-3800
TSB/Document Date: 2021-04-26
Summary
Some customers may experience the CHECK ENGINE light ON with DTC P0126:00 (Thermostat stuck open) and one or more of the following symptoms: The engine takes longer to warm up, The engine temperature gauge fluctuates, The low coolant temperature indicator (blue) light stays on longer or comes on while driving, Poor heater performance, especially at idle. NOTE: Vehicles with SKYACTIV-G 2.5T are not applicable. Due to production variety of the failsafe thermostat integrated in the coolant control valve, engine coolant may enter into a dry hollow in the failsafe thermostat, resulting in unintended opening of the failsafe thermostat at lower temperatures (104-176 °F (40-80 °C)). To eliminate this concern, the production process of the coolant control valve has been modified.
BULLETIN NOTES
APPLICABLE MODEL(S)/VINS
2019-2021 Mazda3
2018-2021 (US spec) / 2019-2021 (Mexico spec) Mazda6
2019-2021 CX-3
2018-2021 CX-5
2020-2021 CX-30
NOTE: Vehicles with SKYACTIV-G 2.5T (turbo) are not applicable.
DESCRIPTION
Some customers may experience the CHECK ENGINE light ON with DTC P0126:00 (Thermostat stuck open) and one or
more of the following symptoms:
•
•
•
•
The engine takes longer to warm up
The engine temperature gauge fluctuates
The low coolant temperature indicator (blue) light stays on longer or comes on while driving
Poor heater performance, especially at idle
NOTE: Vehicles with SKYACTIV-G 2.5T are not applicable.
Due to production variety of the failsafe thermostat integrated in the coolant control valve, engine coolant may enter into
a dry hollow in the failsafe thermostat, resulting in unintended opening of the failsafe thermostat at lower temperatures
(104-176 °F (40-80 °C)). To eliminate this concern, the production process of the coolant control valve has been
modified.
REPAIR PROCEDURE
1. Verify customer concerns and check the coolant temperature in the freeze frame data.
• If it is at around 104-176 °F (40-80 °C), proceed to step 2.
• If it is not at around 104-176 °F (40-80 °C), this TSB is not applicable. Diagnose according to the instruction on
MGSS.
2. Replace the coolant control valve with a new one according to the instruction on MGSS (COOLANT CONTROL
VALVE REMOVAL/INSTALLATION).
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04/26/2021 08:56 AM tlawrenc
•
•
•
•
•
Mazda3 (COOLANT CONTROL VALVE REMOVAL/INSTALLATION)
Mazda6 (COOLANT CONTROL VALVE REMOVAL/INSTALLATION)
CX-3 (COOLANT CONTROL VALVE REMOVAL/INSTALLATION)
CX-5 (COOLANT CONTROL VALVE REMOVAL/INSTALLATION)
CX-30 (COOLANT CONTROL VALVE REMOVAL/INSTALLATION)
3. Warm up the engine and confirm that the primary malfunction is resolved according to the instruction on MGSS
(Repeatability verification procedure in the DTC P0126:00 [PCM]).
•
•
•
•
•
Mazda3 (DTC P0126:00 [PCM (SKYACTIV-G)])
Mazda6 (DTC P0126:00 [PCM (SKYACTIV-G)])
CX-3 (DTC P0126:00 [PCM (SKYACTIV-G)])
CX-5 (DTC P0126:00 [PCM (SKYACTIV-G)])
CX-30 (DTC P0126:00 [PCM (SKYACTIV-G)])
4. Verify repair.
PARTS INFORMATION
Parts Number
Description
Qty.
Notes
PYFD-15-16Z
Valve, Water Control
1
O-ring included
PYFB-15-169
Gasket, Water Outlet
1
[R] for Lower radiator hose component
[R]: Replacement parts
NOTE: Since the modification has been implemented during the production of the part number without a suffix, it is
necessary to check the suffix and the production date code of the obtained part.
• If available part is PYFD-15-16ZA or with later suffix, the following procedure is not necessary.
1. With a smart phone, scan the two dimensional code on the water control valve.
2. The code consists of three blocks of codes where the sample picture is read as PYFD1516Z 171115 0000063 and the
second block of the code is the production date in YYMMDD format.
• If the second block of the code is 201116 or greater (meaning November 16, 2020 or later), the coolant control
valve is modified.
Page 2 of 3
04/26/2021 08:56 AM tlawrenc
WARRANTY INFORMATION
NOTE:
• This warranty information applies only to verified customer complaints on vehicles eligible for warranty repair.
• This repair will be covered under Mazda
’s Powertrain Warranty term, Calif. Emission Warranty (long term) [except
2018 Mazda6, 2019 CX-3 and 2018 CX-5], or Calif. Emission Warranty (short term) [2018 Mazda6, 2019 CX-3
and 2018 CX-5]
• Additional diagnostic time cannot be claimed for this repair.
Warranty Type
A
Symptom Code
6X
Damage Code
9K
Part Number Main Cause
PYFD-15-16Z
Quantity
1
Operation Number / Labor Hours:
Model
Mada3
CX-3
CX-30
Mazda6
CX-5
See chart below.
Spec
Operation No.
Labor Hours
2.0L
XXT2BARX
2.5L-A/T
XXT2BBRX
2.5L-M/T
XXT2BCRX
1.2 Hrs.
2.0L
XXT2BARX
1.2 Hrs.
2.0L
XXT2BARX
2.5L without cylinder deactiv
ation
XXT2BDRX
2.5L with cylinder deactivati
on
XXT2BERX
1.3 Hrs.
2.5L
XXT2BFRX
1.3 Hrs.
2.0L-M/T
XXT2BGRX
1.2 Hrs.
2.0L-A/T
XXT2BHRX
2.5L
XXT2BFRX
1.3 Hrs.
1.2 Hrs.
1.3 Hrs.
Page 3 of 3
04/26/2021 08:56 AM tlawrenc
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TSB/Document ID: 01-011-21-3800
Replacement Service Bulletin Number:
MFR Communication Date: 2021-04-22
MFR Internal Campaign ID/Software Version:
Communication Type: Service Bulletin/Repair Instructions
NHTSA Components: ENGINE AND ENGINE COOLING
MFR Component System:
MFR Component Subsystem:
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