Frequently Asked Questions

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

• Initial diagnostic: we perform a thorough scan and inspection to identify codes and causes; many diagnostics are competitively priced and sometimes complimentary with service.
• Immediate savings: our dealership often costs less than independent shops because we combine fast diagnostics with accurate repairs, minimizing repeat visits and parts misdiagnosis.
• Long-term savings: correct repairs reduce fuel use, prevent catalytic converter damage and avoid higher future repairs; factory-trained techs get it right the first time.
• Warranty note: any repairs covered under warranty must be performed at a certified dealership like Nalley Toyota of Roswell to preserve coverage.

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

• General alert: the light means the vehicle’s computer detected an emissions, engine or drivetrain issue that needs evaluation.
• Common triggers: loose gas cap, oxygen sensor, catalytic converter inefficiency, ignition misfire or fuel-delivery irregularities.
• Severity varies: some faults are minor and safe to drive to our shop; others require immediate attention to avoid further damage.
• Professional scan: our technicians read specific fault codes with OEM tools, explain the results, and recommend the most cost-effective repair path.

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

• Simple checks: confirm the gas cap is tightened — a loose cap is a common cause and can clear the code after a short drive.
• Monitor symptoms: note drivability changes such as stalling, rough idle, power loss or unusual noises to help our technicians prioritize diagnosis.
• Bring it in: if the light remains on or returns, visit Nalley Toyota of Roswell so factory tools can retrieve stored codes and freeze-frame data.
• Warranty reminder: if your vehicle is under warranty, repairs must be done at a certified dealership to maintain coverage and ensure genuine parts.

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

• Top cause: a loose or faulty gas cap frequently triggers emissions codes and is an easy first fix.
• Sensors and emissions: failing oxygen sensors, EVAP leaks or catalytic converter issues are common and affect performance and fuel economy.
• Electrical/ignition: misfires from spark plugs or coils can also flag the light and should be addressed promptly to avoid engine or converter damage.
• Certified care: our dealership handles these issues efficiently using OEM diagnostics, often saving you money over repeated independent attempts.

How long does a check engine light service take?

• Diagnostic time: a full scan and initial inspection typically takes 30–60 minutes depending on symptoms and stored data.
• Repair time: simple fixes like tightening a gas cap or replacing a sensor can be completed the same day; complex repairs vary from a few hours to a day or more.
• Efficiency: factory-trained technicians and genuine parts speed repairs and reduce the chance of follow-up visits, saving time and money long-term.
• Service options: we offer quick scheduling, loaner vehicles or shuttle service at Nalley Toyota of Roswell to keep you moving while we work.