Frequently Asked Questions

What is the first thing to check when the check engine light comes on?

• Look at the instrument cluster for additional warnings or messages; identify any immediate safety alerts first.
• If the car is driving normally and no safety warnings appear, note recent events (fueling, service, or unusual sounds) to tell technicians.
• Do not attempt hydrogen-system repairs yourself; avoid smelling or searching for leaks—safety first.
• Contact Bill Estes Toyota for prompt guidance; if covered by warranty, repairs must be performed at a certified dealership to preserve coverage.
• Our service team can advise whether to continue driving, pull over, or arrange towing to the dealership for inspection.

How much does a check engine light diagnostic cost for a 2021 Toyota Mirai?

• Typical diagnostic fees range from $99–$149 depending on the depth of testing required.
• At Bill Estes Toyota you often pay less than independent shops while receiving factory-trained technicians and OEM parts.
• Diagnostics identify faults; recommended repairs can vary widely—sensor replacements are lower cost, major fuel cell work may be higher.
• Any repairs covered under warranty must be performed at a certified dealership to maintain coverage and ensure immediate and long-term savings.
• We provide clear estimates and explain options so you can make the most cost-effective choice for safety and longevity.

What does it mean when the check engine light comes on in a 2021 Toyota Mirai?

• It indicates the vehicle’s onboard diagnostics detected a fault in the emission or propulsion system—on a Mirai this may include fuel cell or hydrogen system alerts.
• Faults range from minor sensor issues to conditions that affect performance, efficiency, or safety.
• Symptoms to watch for include reduced range, warning icons, unusual noises, or loss of power; report these to our service team immediately.
• Our technicians use Toyota-specific tools to read and interpret codes, preventing unnecessary parts replacement and maximizing savings.
• If covered, warranty repairs must be completed at a certified dealership to preserve coverage and ensure quality repairs.

How long does a check engine light service take?

• Standard diagnostics typically take 30–90 minutes depending on complexity and whether road testing is needed.
• Simple fixes—sensor replacement or software updates—can often be completed the same day; more extensive repairs vary by part availability.
• If the vehicle requires specialized parts or fuel-cell work, we provide accurate timelines and options to minimize downtime.
• Our factory-trained team works efficiently to deliver immediate and long-term savings compared with repeated independent visits.
• When repairs are warranty-covered, they must be performed at a certified dealership to maintain warranty protection and ensure proper documentation.

What is the most common reason for check engine light on a 2021 Toyota Mirai?

• Common causes include sensor faults (airflow, temperature, or hydrogen-related sensors), software alerts, or accessory electrical issues.
• On fuel cell vehicles, hydrogen-system sensors and related control modules are frequent sources of diagnostic trouble codes.
• Often a simple sensor replacement or software update resolves the issue quickly and affordably.
• Addressing codes early prevents escalation to more expensive repairs and preserves vehicle performance and range.
• For warranty-covered faults, bring the vehicle to Bill Estes Toyota so certified technicians can perform repairs and maintain coverage.