Service bulletin T-SB-0043-23 Rev1

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)
Type	Service bulletin
NHTSA id	11015506
Published by NHTSA	2025-03-11
Manufacturer's number	T-SB-0043-23 Rev1
Manufacturer's date	2025-02-20
Campaign id or software version	T-SB-0043-23 Rev1
NHTSA component	ENGINE

NHTSA's summary

Some 2021 – 2022 model year Mirai vehicles may exhibit a MIL ON condition with one or both of the following Diagnostic Trouble Codes (DTCs) present: •P1F6C71 – Air Sealing Valve Actuator Stuck •P1F6E71 – Air Pressure Regulating Valve Actuator Stuck The EV control computer logic has been modified to reduce the possibility of this condition.

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

P1F6C, P1F6E

Vehicles listed
TOYOTA MIRAI	2021, 2022

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

Other bulletins for the same vehicles and component
T-SB-0110-20 Rev2	2026-09-09. Service bulletin. OBSOLETE NOTICE August 20, 2026: This bulletin is now obsolete. Please see T-SB-0051-26.
T-SB-0051-26	2026-09-09. Service bulletin. This bulletin includes basic procedures for performing a rescue charge at battery on high voltage (HV) Ni-MH and Li-ion batteries.
26TE03	2026-06-04. Warranty extension. Although the Mirai Electric Heater Assemblies are covered by Toyota’s New Vehicle Limited Warranty for 3 years or 36,000 miles (whichever comes first), we at Toyota care about the customers’ ownership experience. Under this program, Toyota is providing additional coverage for repairs related to Mirai electric heater assembly potentially becoming inoperative.
26TE03	2026-06-04. Service bulletin. TECHNICAL INSTRUCTIONS FOR 26TE03 ELECTRIC HEATER SUB-ASSEMBLY REPLACEMENT CERTAIN 2021 - 2024 MIRAI
T-SB-0043-23 Rev1	2025-04-08. Service bulletin. Some 2021 – 2022 model year Mirai vehicles may exhibit a MIL ON condition with one or both of the following Diagnostic Trouble Codes (DTCs) present: •P1F6C71 – Air Sealing Valve Actuator Stuck •P1F6E71 – Air Pressure Regulating Valve Actuator Stuck The EV control computer logic has been modified to reduce the possibility of this condition.
T-SB-0021-25	2025-04-08. Service bulletin. Flash reprogramming allows the Electronic Control Unit (ECU) software to be updated without replacing the ECU. Flash calibration updates for specific vehicle models/ECUs are released as field-fix procedures described in individual Service Bulletins. This bulletin details the Global Techstream+ (GTS+) ECU flash reprogramming procedures and outlines use of the Technical Information System (TIS) and the Calibration Update Wizard+ (CUW+). To ensure the correct ECU software is installed, ECUs will require a Security Signature before the ECU will initialize the flash reprogramming sequence. This bulletin also details the process for acquiring a Security Signature from TIS during the GTS+ ECU flash reprogramming process.
T-SB-0107-20 Rev2	2025-03-25. Service bulletin. OBSOLETE NOTICE February 11, 2025: This bulletin is now obsolete. Please see T-SB-0021-25.
T-SB-0021-25	2025-03-11. Service bulletin. Flash reprogramming allows the Electronic Control Unit (ECU) software to be updated without replacing the ECU. Flash calibration updates for specific vehicle models/ECUs are released as field-fix procedures described in individual Service Bulletins. This bulletin details the Global Techstream+ (GTS+) ECU flash reprogramming procedures and outlines use of the Technical Information System (TIS) and the Calibration Update Wizard+ (CUW+). To ensure the correct ECU software is installed, ECUs will require a Security Signature before the ECU will initialize the flash reprogramming sequence. This bulletin also details the process for acquiring a Security Signature from TIS during the GTS+ ECU flash reprogramming process.
T-SB-0110-20 Rev2	2025-01-09. Service bulletin. This bulletin includes basic procedures for performing a rescue charge at battery on high voltage (HV) Ni-MH and Li-ion batteries. This bulletin should be used in conjunction with the applicable model and model year Repair Manual while performing the battery rescue charge. The GRX-5100 should be used wherever the Repair Manual references the Toyota Hybrid System (THS) charger.
T-PANT-2024-004-	2024-04-15. Service bulletin. This is to advise of various price adjustments that will affect Toyota Genuine Motor Oil and Long Life Coolant, effective March 1, 2024. These products are ordered through the Toyota Complete Maintenance Care (TCMC) website.