2016-2025 Toyota Mirai Problems: 9 Known Issues

How to Fix

Have an authorized Toyota Mirai dealer check the VIN and current campaign status. Campaign 22TC04 addresses the no-start software condition; its update also covers 22TD01. The separate 22TD01 offer expired on November 11, 2024, so do not assume that offer remains available. For the specific 22TC04 no-start condition and warning, Toyota instructs switching the vehicle off and waiting 10 full minutes without restarting before trying again. This is not advice to restart after an unexplained loss of drive power. For a check-engine light, T-SB-0043-23 Rev1 (February 20, 2025) requires P1F6C71 and/or P1F6E71, a pre-change VIN and an older EV-control calibration. Missing codes or current calibration means further diagnosis, not automatic replacement. The P1F6C71 branch replaces the air sealing valve; the P1F6E71 branch replaces the air pressure regulating valve. Each replacement valve needs two FC-stack-air gaskets; replacing both requires four. The technician then updates the EV Control Computer, clears codes and verifies the condition is gone. Do not replace the computer for this bulletin. Fuel Cell System Warranty coverage is 96 months or 100,000 miles from in-service, subject to the specified condition and warranty rules; this is not a recall or guaranteed free repair. Any loss of motive power or unrelated warning requires diagnosis, not a guessed valve purchase.

How to Fix

Monitor range and performance regularly. If range drops more than 20% from new, contact Toyota dealer for fuel cell stack diagnostic. The stack may need reconditioning or replacement (covered under warranty for 8 years/100,000 miles). Always refuel at stations with known clean hydrogen supply. Avoid letting the tank run very low, as air intrusion into the fuel system can damage the membrane.

Owner tips & cautions

• TipTrack your miles-per-kg at every fill. If it drops below 50 miles/kg consistently (Gen 1), start a warranty claim. Toyota has been good about replacing stacks under warranty.

How to Fix

If range drops noticeably from what your car used to achieve, or a fuel cell warning appears, have a Toyota dealer check the fuel cell system. Summarized from the owner reports linked here; not a manufacturer finding. Your vehicle's equipment and history may differ; a technician must confirm the cause.

How to Fix

Toyota dealers will update the parking assist software free of charge, restoring the live reverse camera image. The recall is tracked by Toyota as 25TB13 and 25LB06, and owner letters were mailed January 2, 2026. Mirai owners can confirm inclusion by VIN at nhtsa.gov/recalls or by calling Toyota customer service at 1-800-331-4331 - useful since Mirai service is limited to certain dealers in fuel cell markets.

How to Fix

Have a Toyota dealer verify open recall 22TA03 / NHTSA 22V-239 by VIN. The remedy is a free Skid Control ECU software update, not replacement of the brake actuator. Toyota estimates about one hour, with appointment time varying. Until repaired, the owner letter says to fully release the brake pedal between ignition cycles; if VSC is off at startup, use the VSC/TRAC control to reactivate it. Do not deliberately reproduce the fault or drive with stability control disabled to test this illustration.

How to Fix

Ask a Toyota Mirai dealer to check T-SB-0085-23 Rev1. The repair path requires the below-freezing warning, P1C8449 and/or P300449, and a pre-production-change VIN. The technician inspects both SMRB/SMRG relay supplier/date codes: the countermeasures are July 2021 for Panasonic and December 23, 2022 for Denso. A different supplier, a newer relay, missing codes or a different condition requires further diagnosis, not automatic replacement. Where the bulletin applies, replace the specified high-voltage junction-block/relay assembly, clear codes and verify operation. High-voltage work is for trained technicians. Mirai uses the Basic Warranty branch, 36 months or 36,000 miles from in-service, not the other models’ 60-month/60,000-mile branch. This is not a recall or guaranteed free repair.

How to Fix

Have a Toyota Mirai dealer check T-SB-0080-21, the grade-specific production-change VIN and DTC P060A47. If the code is absent or the computer already has current calibration, the bulletin directs further diagnosis. For an applicable older calibration, reprogram the FCV computer, complete the modification label, clear codes and verify proper operation. Toyota explicitly says not to replace the computer. The listed Fuel Cell Component Warranty is 96 months or 100,000 miles from in-service and applies only to the specified occurrence and warranty conditions; it is not a recall or a promise of free repair.

How to Fix

Contact an authorized Toyota Mirai dealer if the heater has stopped working. Ask them to verify the condition, VIN and date of first use under Customer Support Program 26TE03. Eligible vehicles receive the electric heater assembly replacement at no charge for 10 years from first use, without a mileage limit. The technician follows the high-voltage isolation checks, uses the specified FC stack coolant, checks for leaks and confirms heater/defroster operation. This is not a DIY procedure or a reason to replace a working heater. Salvage, total-loss and unknown-mileage vehicles are excluded, with other program exclusions applying. Diagnosis outside coverage may be chargeable; the program also describes reimbursement for qualifying earlier paid repairs.

How to Fix

Ask a Toyota dealer to verify T-SB-0047-23 Rev1 and the production-change VIN. They must reproduce the rear creak/click and pinpoint the member stoppers with a chassis listening tool before choosing this repair. The bulletin replaces two front upper and four lower stoppers after safely disabling the high-voltage system and lowering the rear member. It then requires a test drive; persistent noise has an additional member reseating and retorque branch. Soapy water is a temporary diagnostic aid in the bulletin, not the repair. Basic Warranty is 36 months or 36,000 miles from in-service, subject to its conditions; this is not a recall or guaranteed free work.