Frequently Asked Questions

How much does a check engine light diagnostic cost for a 2019 Toyota Mirai?

• Diagnostic fees vary by complexity; many initial scans are quick, and fees are often applied toward needed repairs.
• At Nalley Toyota of Roswell, our pricing is competitive and often costs less than independent shops while providing factory-trained technicians and Toyota-specific equipment.
• Choosing us delivers immediate savings through accurate diagnosis and long-term savings by preventing larger failures with proper repairs.
• Repairs covered under warranty must be completed at a certified dealership to preserve coverage and ensure parts and labor meet Toyota standards.
• Check our Service Specials for current offers: Service Specials.

What does it mean when the check engine light comes on in a 2019 Toyota Mirai?

• The light indicates the vehicle’s onboard diagnostics detected a fault in systems monitored by the ECU, including fuel cell components, emissions controls, battery management, or sensor circuits.
• For the Mirai, common triggers include hydrogen system sensors, pressure or leak detection faults, fuel cell stack issues, or electrical sensor failures.
• Some faults are minor and safe to drive to the dealership, while others require immediate attention; a prompt professional scan identifies severity.
• Our technicians use Toyota-specific diagnostic tools to read codes and recommend repairs that protect long-term performance and warranty coverage.

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

• Start with a visual check for obvious issues: fluid leaks, warning messages on the dash, or unusual noises. Hydrogen vehicles may show system messages indicating restricted operation.
• A quick on-site scan at our service center will read fault codes and clarify whether immediate action is required or if the vehicle can be driven safely to our shop.
• If a warning indicates a potential hydrogen or safety issue, stop driving and contact Nalley Toyota of Roswell immediately for guidance and safe transport options.
• Remember: repairs under warranty must be completed at a certified dealership to maintain coverage and ensure proper parts and labor.

What is the most common reason for check engine light on a 2019 Toyota Mirai?

• For the Mirai, common reasons include sensor faults in the hydrogen delivery system, fuel cell stack alerts, or electrical sensor failures that affect emissions controls and performance.
• Unlike gasoline cars, fuel-cap issues aren’t applicable; Mirai-specific components like hydrogen pressure sensors or fuel cell cooling systems are frequent triggers.
• Because hydrogen and fuel cell systems are specialized, prompt dealership diagnostics prevent escalation and protect expensive components.
• Our factory-trained technicians diagnose Mirai-specific codes quickly, often saving you money versus prolonged independent troubleshooting and guarding warranty eligibility.

How long does a check engine light service take?

• Simple code reads and basic inspections often take 30–60 minutes; more complex fuel cell or electrical diagnoses can take several hours or longer depending on required tests.
• If parts or in-depth testing are needed, we provide transparent timelines and cost estimates so you can plan accordingly.
• Choosing Nalley Toyota of Roswell delivers immediate value: accurate diagnosis reduces repeat visits and long-term repair costs, and many issues are resolved faster thanks to factory tools and training.
• Repairs covered by warranty must be performed at a certified dealership to ensure coverage and quality of work.