Frequently Asked Questions

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

• Confirm basic conditions: fuel level, loose or missing gas cap, and recent refueling—these are quick checks that often resolve warnings.
• Inspect dashboard for other alerts (temperature, oil pressure) that indicate more urgent problems.
• If the 2025 Toyota Sienna runs rough or stalls, stop driving and have it inspected to avoid further damage.
• For warranty-covered issues, repairs must be performed at a certified dealership to maintain coverage.
• When in doubt, bring your 2025 Toyota Sienna to Nalley Toyota of Roswell for fast, factory-level diagnosis and clear next steps.

How long does a check engine light service take?

• Basic diagnostic scan typically takes 30–60 minutes to read codes and gather live data.
• Repairs can range from a quick fix under an hour (like replacing a gas cap or sensor) to several hours for complex issues; we provide a clear time estimate after inspection.
• Our factory-trained technicians work efficiently, often saving you time compared with independent shops while delivering higher-quality service.
• Warranty repairs must be done at a certified dealership; completing service with us avoids delays and protects coverage.
• We’ll explain immediate needs and long-term considerations so you can make an informed choice that minimizes downtime.

How much does a check engine light diagnostic cost for a 2025 Toyota Sienna?

• Diagnostic fees typically cover the scan and technician time to analyze trouble codes; exact pricing varies—contact Nalley Toyota of Roswell for current rates.
• Dealership service often costs less than independent shops overall because we diagnose correctly the first time, reducing repeat visits and hidden expenses.
• Choosing our dealership provides immediate savings through precise diagnostics and long-term savings from factory-grade repairs and parts that extend vehicle life.
• If a repair qualifies for warranty coverage, it must be completed at a certified dealership to preserve benefits and avoid out-of-pocket expense.
• We provide transparent estimates up front so you understand both short-term costs and long-term value.

What does it mean when the check engine light comes on in a 2025 Toyota Sienna?

• The light is an alert from the vehicle’s onboard computer that a sensor or system is reporting an issue—codes can indicate emissions, ignition, fuel, or sensor faults.
• It does not always mean imminent failure, but it signals the need for prompt diagnosis to prevent escalation into costly repairs.
• Our technicians use OEM-level scanners to read and interpret codes accurately, giving you a reliable plan for repair or monitoring.
• Addressing problems early with Nalley Toyota of Roswell often costs less than waiting and reduces long-term repair bills.
• Remember: warranty-covered repairs must be performed at a certified dealership to maintain coverage and ensure proper parts and procedures.

What is the most common reason for check engine light on a 2025 Toyota Sienna?

• Common causes include loose or faulty gas caps, oxygen sensor faults, catalytic converter inefficiency, or misfires detected by engine sensors.
• A simple loose gas cap is a frequent, low-cost fix—our technicians always check this first during diagnosis.
• More serious issues like misfires or catalytic converter problems require prompt attention to avoid higher repair costs and emissions failures.
• Bringing the vehicle to Nalley Toyota of Roswell ensures accurate diagnosis and repairs by factory-trained technicians who help minimize long-term expenses.
• For warranty-covered defects, staying with a certified dealership is required to keep those protections intact.