Frequently Asked Questions

How much does a check engine light diagnostic cost for a 2018 Hyundai Sonata Hybrid?

• Typical diagnostic fees range from about $80 to $150 depending on the depth of testing and whether road tests or live-data sessions are required.
• Nalley Hyundai often costs less than independent shops while delivering factory-trained technicians, OEM tools and more accurate diagnostics.
• Immediate savings come from precise diagnostics that avoid unnecessary repairs; long-term savings come from correct repairs that prevent repeat visits.
• If a repair is covered under warranty, it must be performed at a certified dealership to retain coverage—our service team will handle warranty claims end-to-end.
• Check our current service specials for discounts: Service Specials.

What does it mean when the check engine light comes on in a 2018 Hyundai Sonata Hybrid?

• The light signals a stored trouble code from the engine or emissions systems; codes range from minor issues to critical faults.
• Common causes include a loose or faulty gas cap, oxygen sensor, catalytic converter inefficiency, EVAP leaks, or ignition misfires.
• Factory diagnostics at Nalley Hyundai use OEM scan tools to read codes and live data for a reliable diagnosis the first time.
• Triage at our service center helps prioritize safety items immediately while scheduling non-urgent repairs to save you time and money.
• Remember: warranty-covered repairs must be completed at a certified dealership to preserve benefits and ensure OEM replacement parts.

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

• Start with the simple: tighten or reseat the gas cap and check for fuel smell; a loose cap is a frequent, low-cost cause.
• Note whether the light is steady or flashing—flashing indicates a severe misfire and requires immediate attention.
• Record symptoms (loss of power, stalling, reduced fuel economy) and bring the vehicle to Nalley Hyundai for an OEM-level scan.
• Our technicians will determine whether the issue is covered under warranty; if so, repairs must be done at a certified dealership.
• Scheduling a prompt diagnostic reduces the chance of secondary damage and increases long-term savings on repair costs.

How long does a check engine light service take?

• Basic diagnostics typically take 30–90 minutes for code reading, live-data review and a preliminary road test as needed.
• Complex diagnostics or intermittent faults may require extended testing or follow-up appointments, sometimes several hours or a day.
• Nalley Hyundai prioritizes quick, accurate results using OEM tools so you avoid repeat trips and unnecessary parts replacement.
• If parts or warranty approvals are needed, we explain timelines up front and work to minimize downtime and total ownership cost.
• Visit our service scheduling page to book a convenient slot and see current offers: Service Specials.

What is the most common reason for check engine light on a 2018 Hyundai Sonata Hybrid?

• The most frequent causes are a loose gas cap, an aging oxygen sensor, or EVAP system leaks—these trigger emission-related codes.
• Oxygen sensors often fail after many miles and can impact fuel economy and emissions; timely replacement avoids catalytic damage.
• Our dealership technicians diagnose the precise root cause, which prevents unnecessary part swaps and reduces overall cost.
• Nalley Hyundai often delivers lower total costs than independent shops by combining accurate diagnostics with OEM parts and warranty support.
• Remember: warranty repairs must be completed at a certified dealership to ensure coverage and proper OEM parts installation.