My Toyota Mirai says "FCV system malfunction" and won't go into drive. What now?

Short answer: If your 2021 Mirai shows 'FCV system malfunction', ask a Toyota dealer to check for campaign 22TD01, a free software update for a false warning, and bulletin T-SB-0080-21 for code P060A47. If the car is completely dead with no lights, check the 12-volt battery in the trunk first. Owners say it's about $199. Don't try to drive on a real FCV warning. Call Toyota roadside.

Symptom: An 'FCV system malfunction' message, other warnings, a car that won't go into drive, or a car that shows no signs of life at all.

What to check first

1. If nothing lights up, check the 12-volt battery in the trunk with a meter.
2. Write down or photograph every message on the dash.
3. Ask the dealer to check for campaign 22TD01 and bulletin T-SB-0080-21 on a 2021 Mirai.
4. Ask for the fault codes in writing.
5. Run your VIN at nhtsa.gov/recalls.

Likely causes

1. False warning from control-computer software (2021). Toyota ran a customer support campaign (22TD01) on some 2021 Mirais to update the EV control computer software because it could show an FCV system malfunction message when nothing was wrong. FCV means fuel cell vehicle.
2. Control-computer fault code P060A47. Toyota bulletin T-SB-0080-21 covers 2021 Mirais with code P060A47, a watchdog fault in a control computer, and fixes it by reprogramming the FCV control computer.
3. Dead or weak 12-volt battery. The Mirai has a small 12-volt battery in the trunk that wakes up the car. If it's dead, nothing lights up.

What it usually costs

The 22TD01 update is free on covered cars, and Toyota lists the P060A47 fix under the fuel cell warranty. Owners put a 12-volt battery at about $199.

Is it safe to keep driving?

If the car won't shift into drive, it's not going anywhere. Call Toyota roadside and ask for a flatbed. If a warning shows while driving, pull over safely.

DIY or shop?

Checking the 12-volt battery is DIY. Everything in the fuel cell and hydrogen system is dealer work. The hydrogen tanks are under high pressure. Never open fittings.

Recalls, bulletins and complaints in plain words

• Recalls: NHTSA lists 3 recall(s) for the Toyota Mirai in these years, and none match this problem. Check your VIN at nhtsa.gov/recalls. If your car is part of a recall, the dealer fixes it for free.
• Plain words: The complaint count below shows how often owners reported problems that mention these words to NHTSA. A count is not proof of a defect.
• NHTSA complaints: 11 keyword-matched complaints for Toyota Mirai 2016–2023 (of 31 unique complaints queried, NHTSA complaints API by model year, queried 2026-10-31; keywords: fcv, fuel cell, malfunction, won t (start, shift), stall, loss of power, shift) (NHTSA returned no data for 5 model-year queries). This counts complaints that mention these words. It is not a defect finding.

What owners report

• In FCV Malfunction in 2021 Mirai XLE on Reddit r/Mirai, an owner of a 2021 Mirai XLE had the car two weeks when several warnings stopped it from going into drive. Toyota roadside towed it, and on Monday it started right up at the dealer, who couldn't say what caused it but said they had seen it before. Another owner later posted the same error from the side of the road.
• In Mirai won't start on Reddit r/Mirai, someone with a 2017 Mirai that showed no lights at all when they tried to start it was told to check the 12-volt battery first. Use the physical key to open the trunk, look under the cover on the right, and check the voltage. Owners said it's a sealed AGM battery, about $199, and not to try jump-starting it with odd power sources.
• Toyota's notice for campaign 22TD01 (June 2022) covers certain 2021 Mirais. It says the EV control computer software can show an 'FCV system malfunction' message that isn't real, and dealers update the software at no cost.
• Toyota bulletin T-SB-0080-21 covers some 2021 Mirais that set code P060A47 and tells dealers to reprogram the FCV control computer. Toyota says the repair falls under the fuel cell warranty, listed as 8 years or 100,000 miles.

Quick tip

If you've got a 2021 Mirai, call the dealer and ask whether 22TD01 and T-SB-0080-21 apply to your VIN before you get stranded, not after.

Vehicle focus: Toyota Mirai, 2016-2023, especially the 2021 model.

Safety / mechanic note

Hydrogen and high-voltage parts are dangerous to work on. Verify with a mechanic.