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Service bulletin 01-001-26b

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id11030598
Published by NHTSA2026-04-02
Manufacturer's number01-001-26b
Manufacturer's date2026-03-04
NHTSA componentENGINE; UNKNOWN OR OTHER
Manufacturer's systemCooling System

NHTSA's summary

Some customers may experience a check engine light ON with DTC P0126:00 (Thermostat stuck open) and one or more of the following symptoms: Engine takes longer to warm up. Engine temperature gauge fluctuates. Low coolant temperature indicator (blue) light stays on longer or turns on while driving. Poor heater performance, especially at idle. Vehicles with SKYACTIV-G 2.5T are not applicable to this service information. DTC P0126:00 is not required to be present to perform this repair. If the vehicle has not previously had the repair specified in this TSB and is exhibiting any of the listed symptoms, proceed with the repair procedure outlined in this bulletin. If DTC P2B61:00 (Coolant Control Valve Circuit Range/Performance) is present along with DTC P0126:00, this TSB does not apply. Diagnose the symptom and/or stored DTCs according to the procedures in MGSS. If only DTC P0126:00 is present and this TSB has already been completed previously, this bulletin does not apply, diagnose the symptom and/or stored DTCs according to the procedures in MGSS. This concern may be caused if the coolant control valve fail-safe thermostat opens at a temperature lower than the normal temperature due to a deformation of the thermostat diaphragm. To eliminate the concern, the water flow control valve specification has been modified. Affected vehicles will require PCM reprogramming with the Mazda Modular Diagnostic System (M-MDS), using either a) Mazda Diagnostic and Repair Software (MDARS) or b) Mazda Integrated Diagnostic System (IDS) 140.04 or later software.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Engine

Trouble codes named

P0126, P2B61

Vehicles listed
MAZDA CX-32019, 2020, 2021
MAZDA CX-302020, 2021, 2022, 2023
MAZDA CX-52018, 2019, 2020, 2021, 2022, 2023, 2024, 2025
MAZDA MAZDA32019, 2020, 2021, 2022, 2023
MAZDA MAZDA62018, 2019, 2020, 2021

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Recalls for the same vehicles and component
20193222019-06-27. Engine
19V4970002019-06-27. POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); ENGINE

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
SA-060-262026-10-01. Service bulletin. NOTE: This service information only applies to vehicles with PYUKD engine and EGR. DESCRIPTION DTC P0402 EGR malfunctions may be falsely detected due to an internal malfunction of the MAP sensor. REPAIR PROCEDURE 1. Using MDARS, verify DTC P0402 is set in current or past history.
SA-038-26a2026-09-04. Service bulletin. This Service Alert supersedes the previously issued service alert listed below. The changes are noted in Red text. SA-038/26 06/15/26 DESCRIPTION Some customers may complain about any of the following: 1. Infotainment Center Display does not provide the Authorization Code (OTP) during the MyMazda App Connected Vehicle enrollment. 2. Remote functions inoperative. Engine Start / Stop Door Lock / Unlock Lights ON / OFF Climate Control 3. MAZDA CONNECT connected vehicle reception strength icon shows "X" or " ". Index MAZDA CONNECT 2 Center Display Status Icon MAZDA CONNECT 3 Center Display Status Icon Remote Engine Start Will Not Function Remote Engine Start Function Will turn engine OFF Customer Subscription Status TCU Communication Line Status
SA-048-262026-09-04. Service bulletin. Some vehicle may exhibit the CHECK ENGINE light on with DTC P0524 (Engine oil pressure control system: Oil pressure decrease) and no abnormal engine noise. This may be caused by a malfunction of the oil pressure control valve (located at the rear of the engine block near the oil filter) due to machining contamination inside the electromagnet sleeve and the solenoid plunger remaining during manufacturing. This contamination is affecting the OCV operation when oil pressure control is requested by the PCM. REPAIR PROCEDURE Perform the WSM inspection for P0524.
01-010-262026-09-02. Service bulletin. This bulletin supersedes the previously issued bulletin(s) listed below. The changes are noted in Red text. 01-012/22 10/06/22 DESCRIPTION Some vehicles may exhibit accumulation of dried coolant (1) around the water pipe (2). This is caused by a gap between the housing and pipe due to a press fitting during the manufacturing process. The accumulated coolant is solidified and plugs the gap in high temperature environment and the seepage is stopped and does not progress. This is normal and does not require a part replacement, clean off the dried coolant from around the pipe with a wire brush. REPAIR PROCEDURE 1. Verify the customer concern. 2. If the above condition is experienced, remove the accumulated coolant around the pipe (1) with a wire brush etc. NOTE: Perform the procedure on the vehicle. No need to remove the water pipe and hoses.
SA-042-262026-07-03. Service bulletin. This Service Alert supersedes the previously issued SAs listed below. The changes are noted in Red text. SA-017/25 12/16/25, 09/08/25, 07/14/25, 05/15/25 and 03/21/25 DESCRIPTION Mazda Connect Frequently Asked Questions (FAQ) Index General Questions MAZDA CONNECT Indication Setup and Getting Started Dealer Processes Registration / Enrollment / Take-Over Customer Subscription Status WI-FI General Informatio Opening the TCU Communication Line WI-FI How-To Conditions for Remote Engine Start Will Not Function WI-FI Trial Period Conditions for Remote Engine Start Function Will turn engine OFF Interacting With The App TCU Communication Line Status Service Issues Educational Videos Troubleshooting Resources MyMazda App Error Codes Customer Opt-Out
SA-041-262026-07-03. Service bulletin. This SA supersedes the previously issued SA(s) listed below. The changes are noted in Red. SA-061/25 12/17/25 DESCRIPTION If you encounter any type of electrical concern (e.g, dead battery, engine no start, DTC(s) stored...), interview the customer before proceeding with normal MGSS diagnosis by asking if any aftermarket devices have been installed. Aftermarket devices may be the cause of the electrical concern. Below are a few examples of unusual electrical concerns caused by aftermarket devices. Examples: 1. Devices connected to the DLC-2 (battery discharge/DTC stored) 2. Devices plugged into the 12V outlet 3. GPS tracking device (engine no start/battery discharge) 4. Dash cam (DTC stored) 5. Non-certified USB cable (Apple Carplay™/ Android Auto™ will not connect) 6. Over-sized wheels/tires (incorrect GPS location) 7. DTC C0023:14 8. Decorative trim and/or cover on the START/STOP ENGINE button Example 1: Some electrical devices connected to the DLC-2 connector by insurance or mobile phone companies may cause: Battery discharge. The device may disrupt the CAN system battery saver mode. • IDS/MMDS will not communicate with the vehicle due to poor DLC-2 connection. The aftermarket device may cause DLC-2 female terminals to spread open.
09-019-262026-07-03. Service bulletin. This bulletin supersedes the previously issued bulletin(s) listed below. The changes are noted in Red. 09-012/21 12/13/21, 06/10/21 and 04/27/21 DESCRIPTION Some customers may experience all of following symptoms: The door lock/unlock operation will not work using the remote transmitter button. 1. The door lock/unlock operation will not work using the door lock/release touch sensor. 2. The engine will not start using the ignition switch. 3. The transmitter operates by itself. 4. The key battery drains faster than usual. 5. Symptoms 1-3: This may be caused when excess load is applied to the remote transmitter, deforming the electrical terminals and creating poor contact with the battery. To eliminate this concern, the structure in the remote transmitter has been modified to reduce the deformation of the electrical terminals. Symptom 4-5: This may be caused when excessive load is applied to the remote transmitter, creating a gap around the gasket where moisture enters and corrodes the circuit board which in turn drains the key battery faster than usual. To eliminate this concern, the thickness of the case wall on the gasket mounting surface has been increased and the bonding strength of the components has been improved to prevent deformation. REPAIR PROCEDURE • If the battery is bad or installed incorrectly, replace the battery and/or install it correctly. • If the remote power saving function is off and the battery is good and installed correctly, replace the defective remote transmitter with a modified one according to the instructions on MGSS (IMMOBILIZER SYSTEM-RELATED PARTS PROGRAMMING). NOTE: DO NOT replace other remote transmitter(s) for the vehicle if they not experiencing an issue.
SSPD5 Parts Warr b2026-05-05. Warranty extension. Valve Stem Seals Class Action Settlement Program for Excessive Oil Consumption and Oil Consumption Powertrain Warranty Extension Special Service Program SSPD5. Updated April 28, 2026 – Related oil part number for warranty claims is now 0000-77-5W30-QT (engine oil) as the 5555 warranty part number has been removed. As a reminder, all coverage reverts back to the original extension of 7 years or 84,000 miles whichever comes first. WARRANTY EXTENSION If you have any questions regarding this campaign, please read the Mazda Dealer FAQ’s available in MGSS under this campaign before contacting Dealer Recall Help. Effective October 25,2025: In the final settlement agreement, which was approved by the Court in October 2024, there is also coverage for Valve Stem Seal related repairs for an additional 1 year and 12,000 miles however, this coverage only applies if the vehicle is presented to a Mazda dealer by October 15, 2025 and has no more than 96,000 miles. This additional 1-year coverage has expired. As of October 25, 2025 all coverage under SSPD5 has reverted to the original extension limit of 7 years, 84,000 miles including the Powertrain Limited Warranty Extension is of 7 years, 84,000 miles. Update August 2025: The Court has clarified that under the settlement agreement, the Mazda Powertrain Limited Warranty Extension includes coverage for 7 years or 84,000 miles, whichever comes first, for all powertrain components in the Warranty Booklet under the Powertrain Limited Warranty Parts List (i.e. without restriction to engine issues, oil consumption or valve stem seal issues). Reimbursement will also be provided for any Class Member who was denied coverage and paid out-of-pocket for a qualifying Powertrain Limited Warranty repair during the applicable period.
SA-029-262026-05-05. Service bulletin. This Service Alert supersedes the previously issued SA listed below: The changes are noted in Red. SA-011/24 02/12/24, 06/06/24, 07/29/24 DESCRIPTION Mazda has developed factory recommended scheduled maintenance services that support all major vehicle systems. Mazda recommends dealers follow the scheduled maintenance tables as cited in the vehicle-specific workshop manual or owner's manual. Services performed outside of Mazda's factory scheduled maintenance are not recommended. These services are unnecessary and create unneeded expenses for your customers. SCHEDULED MAINTENANCE Refer to the applicable Workshop Manual or Owner's Manual for vehicle -specific manufacturer scheduled maintenance. Workshop Manual - Refer to section 00-00 SCHEDULED MAINTENANCE. Owner's Manual - Refer to section 8 Maintenance and Care. b. Note: Please refer to the information below outlining the services not included in Mazda's Factory Scheduled Maintenance: IMPORTANT: Recommending fluid flushes when not necessary can lead to customer confusion and dissatisfaction. Fluid flushing for preventive maintenance purposes is strongly discouraged, unless otherwise specified in a published procedure (Owner’s Manual, Workshop Manual, Technical Service Bulletin, etc.).
SA-026-262026-05-05. Service bulletin. This Service Alert supersedes the previously issued M-Tip(s) listed below. The changes are noted in Red text. MT-002/19 09/30/19 and 12/19/19 DESCRIPTION If an engine assembly is replaced after a catastrophic internal mechanical failure, clean the intake manifold internally before installing a replacement engine assembly. If the intake manifold is not cleaned properly, the replacement engine may fail prematurely. Metallic debris from the old engine (with catastrophic internal mechanical failure) may rest inside the intake manifold. When the new engine assembly is installed, debris in the intake manifold will be ingested into the new engine and cause internal damage. Clean the intake manifold internally to remove any debris from old engine before installing the new replacement engine assembly. If the intake manifold cannot be properly cleaned internally, replace it.