Frequently Asked Questions

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

• Confirm the gas cap is tight and undamaged — a loose cap is a common and simple cause.
• Look for obvious issues: low oil, visible leaks, or recent fueling mishaps that could trigger the light.
• If the light remains, schedule a dealership scan; repairs covered under warranty must be performed at a certified dealership to remain valid.
• Nalley Toyota Union City can perform a quick inspection and advise on immediate next steps to avoid long-term damage.

What does it mean when the check engine light comes on in a 2024 Toyota Sienna?

• It indicates the vehicle’s engine control module detected a fault — severity ranges from simple EVAP leaks to engine misfires.
• Minor issues may only affect emissions or fuel economy; serious faults can risk engine or catalytic converter damage if ignored.
• Our factory-trained technicians use Toyota diagnostic tools for precise troubleshooting and recommend repairs that preserve warranty coverage.
• Addressing issues early at our dealership often reduces overall cost and downtime compared with repeat visits to independent shops.

What is the most common reason for check engine light on a 2024 Toyota Sienna?

• Common causes include a loose or faulty gas cap, oxygen sensor or catalytic converter issues, and engine misfires from ignition or fuel problems.
• EVAP system leaks (often a simple cap or hose) and aging O2 sensors are frequent triggers that affect fuel economy and emissions.
• Early dealership diagnosis prevents escalation — replacing a sensor or tightening a cap is usually quicker and less costly than repairing secondary damage.

How much does a check engine light diagnostic cost for a 2024 Toyota Sienna?

• Diagnostic fees typically range from modest flat rates for an OBD-II scan to standard shop diagnostic charges for complex troubleshooting; we provide transparent estimates before work begins.
• Nalley Toyota Union City often costs less than independent shops once you factor in accurate diagnosis, OEM parts, and the reduced likelihood of repeat visits — immediate and long-term savings.
• Any repairs covered under warranty must be completed at a certified dealership; using us ensures warranty protection and access to factory-trained technicians and Toyota-approved parts.

How long does a check engine light service take?

• Basic OBD-II diagnostics often take 30–60 minutes; minor repairs like replacing a gas cap or sensor can be same-day tasks.
• More involved repairs requiring parts or in-depth troubleshooting can take several hours to a few days, depending on part availability and the complexity of the issue.
• Nalley Toyota Union City prioritizes accurate diagnosis and efficient repairs, using OEM parts and Toyota tools to reduce callbacks and long-term costs.
• We offer service specials and customer conveniences to minimize downtime—visit our Service Specials page for current offers.