Frequently Asked Questions

How much does a check engine light diagnostic cost for a 2026 Toyota Grand Highlander?

• Typical diagnostic fees range from about $99 to $199 depending on the complexity of the scan and live testing.
• At Nalley Toyota of Roswell we often cost less than independent shops while delivering factory-trained technicians and OEM tools.
• Many issues discovered during diagnosis are eligible for warranty or service programs when repaired at a certified dealership—warranty-covered work must be performed by a certified dealership.
• Choosing dealer service can provide immediate savings by avoiding incorrect fixes and long-term savings through accurate diagnostics and OEM parts.

What does it mean when the check engine light comes on in a 2026 Toyota Grand Highlander?

• A steady check engine light signals a detected fault in the emissions, fuel, ignition, or sensor systems that needs diagnosis.
• Codes range from minor (EVAP leak, loose gas cap) to serious (misfire, catalytic converter issues) and require an OBD-II scan to identify.
• Nalley Toyota of Roswell uses OEM diagnostic tools to pinpoint causes fast, minimizing unnecessary parts replacement and long-term costs.
• If a repair is covered by warranty, it must be completed at a certified dealership to preserve coverage and ensure lasting results.

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

• Start with the basics: ensure the gas cap is properly tightened after fueling—this is a very common cause of an emissions fault code.
• Check for obvious signs such as unusual noises, smoke, or loss of power; if present, stop driving and have the vehicle inspected immediately.
• Bring the vehicle to Nalley Toyota of Roswell for a prompt scan; certified technicians will confirm whether its a minor reset or a repair that preserves long-term reliability and warranty eligibility.
• Addressing the issue at a dealership often results in immediate savings by preventing collateral damage and assuring correct OEM repairs.

What is the most common reason for check engine light on a 2026 Toyota Grand Highlander?

• The most frequent causes include a loose or faulty gas cap, oxygen sensor failure, misfires, or EVAP system leaks—all detectable with an OBD-II scan.
• Ignoring these symptoms can reduce fuel economy, increase emissions, and lead to costly component damage like catalytic converter failure.
• Nalley Toyota of Roswell identifies root causes quickly with OEM diagnostics and genuine parts to reduce immediate repair costs and long-term ownership expenses.
• Remember, repairs covered under warranty must be performed at a certified dealership to maintain coverage and ensure quality workmanship.

How long does a check engine light service take?

• Basic diagnostics typically take 30 minutes to 2 hours; more complex troubleshooting or road tests can extend that time.
• If repairs are required, time varies by the part and severity—simple fixes (gas cap, sensor) can be same-day; major repairs may take longer.
• At Nalley Toyota of Roswell we strive for efficient, accurate service using OEM parts and factory-trained technicians to reduce repeat visits and long-term costs.
• If a repair is covered under warranty, it must be done at a certified dealership to preserve benefits and ensure professional completion.