Service bulletin T-SB-0318-17-Rev

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	10150003
Published by NHTSA	2018-12-03
Manufacturer's number	T-SB-0318-17-Rev
Manufacturer's date	2018-09-05
NHTSA component	ENGINE

NHTSA's summary

TSB: REVISION NOTICE September 5, 2018 Rev1: ? The Parts Information section has been updated. Any previous printed versions of this bulletin should be discarded. Some 2016 ? 2017 model year Mirai vehicles may exhibit a warning message, "FC malfunction, return vehicle to dealer for service." This message is accompanied by Diagnostic Trouble Code (DTC) P1DEF (450 FC Stack Performance). The Fuel Control Module (FCM) calibration has been revised to address 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

P1DEF

Vehicles listed
TOYOTA MIRAI	2016, 2017

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-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.
T-TT-0628-20	2020-11-30. Service bulletin. TT: HVAC drain tube is found to be blocked/clogged.
T-SB-0074-20	2020-09-14. Service bulletin. TSB: Some 2003 ? 2020 model year Prius, Prius C, Prius V; 2006 ? 2019 model year Highlander Hybrid Vehicle; 2007 ? 2020 Camry Hybrid Vehicle; 2013 ? 2020 model year Avalon Hybrid Vehicle; 2016 ? 2020 model year Mirai and RAV4 Hybrid Vehicle; and 2020 model year Corolla Hybrid Vehicles may exhibit a MIL ON condition with Diagnostic Trouble Codes (DTCs) P0A80/P1AC000 and/or P0A7F/P1A8000 stored due to dust or debris buildup in the HV battery cooling fan and/or HV cooling filter. Follow the procedure in this bulletin to address this condition.
T-SB-0074-20	2020-09-14. Service bulletin. TSB: Some 2003 ? 2020 model year Prius, Prius C, Prius V; 2006 ? 2019 model year Highlander Hybrid Vehicle; 2007 ? 2020 Camry Hybrid Vehicle; 2013 ? 2020 model year Avalon Hybrid Vehicle; 2016 ? 2020 model year Mirai and RAV4 Hybrid Vehicle; and 2020 model year Corolla Hybrid Vehicles may exhibit a MIL ON condition with Diagnostic Trouble Codes (DTCs) P0A80/P1AC000 and/or P0A7F/P1A8000 stored due to dust or debris buildup in the HV battery cooling fan and/or HV cooling filter. Follow the procedure in this bulletin to address this condition.
T-TT-0468-17 Rev	2020-08-17. Service bulletin. TT: HVAC drain tube is found to be blocked/clogged.
T-SB-0318-17_Rev	2019-10-15. Service bulletin. TSB: REVISION NOTICE September 20, 2019 Rev2: ? Applicability has been updated to include 2018 and 2019 model year Mirai vehicles. ? The Production Change Information, Parts Information, and Calibration sections have been updated. September 5, 2018 Rev1: ? The Parts Information section has been updated. Some 2016 ? 2019 model year Mirai vehicles may exhibit a warning message, "FC malfunction, return vehicle to dealer for service." This message is accompanied by Diagnostic Trouble Code (DTC) P1DEF (450 FC Stack Performance). The Fuel Control Module (FCM) calibration has been revised to address this condition.
T-SB-0134-16-Rev	2019-09-03. Service bulletin. TSB: REVISION NOTICE July 01, 2019 Rev2: ? Applicability has been updated to 2019 ? 2020 model year Toyota vehicles. ? The Techstream Preparation and Process Overview sections have been updated. October 30, 2017 Rev1: ? Applicability has been updated to include 2018 model year vehicles. Any previous printed versions of this bulletin should be discarded. SUPERSESSION NOTICE The information contained in this bulletin supersedes SB No. T-SB-0012-13. Service Bulletin No. T-SB-0012-13 is obsolete and any printed versions should be discarded. Be sure to review the entire content of this bulletin before proceeding. 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 Techstream ECU flash reprogramming process and outlines use of the Technical Information System (TIS) and the Calibration Update Wizard (CUW). Flash calibration updates can only be applied to the vehicle/ECU combination for which they are intended. ECUs have internal security that will not allow them to be programmed with another ECU?s information. NOTE ECU is a Toyota term used to describe integrated computerized devices responsible for managing the operation of a system or subsystem. For the purposes of this bulletin, the term ?ECU? is used as a generic label for the following SAE J1930 standard references: ? Powertrain Control Module (PCM) ? Engine Control Module (ECM) ? Transmission Control Module (TCM) ? Any other Toyota specific control unit
T-SB-0134-16	2018-11-26. Service bulletin. TSB: Supersession Notice. Flash reprogramming allows the 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 Techstream ECU flash reprogramming process and outlines use of the Technical Information System (TIS) and the Calibration Update Wizard (CUW). Flash calibration updates can only be applied to the vehicle/ECU combination for which they are intended. ECUs have internal security that will not allow them to be programmed with another ECU?s information.
T-SB-0009-16	2018-04-23. Service bulletin. TSB: Hydrogen fuel cell powered vehicles like the Mirai use a special high-insulation coolant designed to prevent high voltage ground faults and associated MIL ?ON? (Malfunction Indicator Light) condition. This special coolant and special water mix MUST be used any time coolant is added to the fuel cell (FC) cooling system reservoir or when major services performed on the fuel cell stack and/or fuel cell cooling system. Use of water or any coolant other than ?Toyota Genuine FC Stack Coolant? could result in damage to the fuel cell stack and/or cooling system.
TSB-0012-13 Rev2	2018-04-23. Service bulletin. TSB: Flash reprogramming allows the 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 Techstream ECU flash reprogramming process and outlines use of the Technical Information System (TIS) and the Calibration Update Wizard (CUW). Flash calibration updates can only be applied to the vehicle/ECU combination for which they are intended. ECUs have internal security that will not allow them to be programmed with another ECU?s information.