Frequently Asked Questions

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

• Typical OBD‑II diagnostics at our dealership start with a thorough scan and inspection; flat diagnostic fees commonly range from $80–$150 depending on complexity.
• Many repairs are covered under warranty; warranty repairs must be performed by a certified dealership to preserve coverage and ensure proper parts and documentation.
• Choosing Nalley Hyundai often costs less than independent shops because our factory-trained technicians diagnose correctly the first time, preventing repeated repairs and lowering long‑term expense.
• We provide clear estimates before any work and discuss options that maximize immediate savings and reduce future maintenance costs.

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

• The light signals the vehicle’s onboard diagnostics has detected a fault — anything from a loose gas cap to emissions, EV drive, battery, or ignition issues.
• For plug‑in hybrids, common causes include O2 sensor faults, catalytic converter efficiency drops, hybrid battery or EV control system alerts, and intermittent misfires.
• Some codes are minor and safe to drive on briefly; others require immediate attention. Our technicians evaluate severity and recommend next steps to protect the vehicle and your wallet.
• If the issue falls under warranty, repairs must be completed at a certified dealership to ensure coverage and genuine parts.

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

• Start with the simple items: confirm the gas cap is tight and properly sealed — a loose cap is a common trigger and easy to fix.
• Note how the car is driving: unusual noises, loss of power, or stalling indicate a higher priority service need and should prompt immediate inspection at our dealership.
• Bring the vehicle to Nalley Hyundai for a prompt scan so factory tools can read hybrid‑specific codes; quick, accurate diagnosis saves time and money over repeated attempts elsewhere.
• Remember, warranty repairs require certified dealer service to keep coverage intact and ensure proper long‑term protection.

How long does a check engine light service take?

• Basic code retrieval and inspection typically take 30–60 minutes; more involved diagnostics or test drives can extend to a few hours.
• If parts or deeper system tests are required, we’ll provide a clear timeline and an estimate — our goal is efficient, accurate work that reduces repeat visits.
• Using Nalley Hyundai often leads to faster resolution versus independent shops because our technicians use factory diagnostics and have immediate access to Hyundai parts and technical resources.
• When warranty work is involved, completing service at our dealership protects coverage and speeds authorization and repair turnaround.

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

• Common causes include oxygen sensor failures, loose or damaged gas caps, catalytic converter efficiency issues, and ignition or misfire events.
• For plug‑in hybrids, battery management or EV control system codes can also trigger the light; these require specialized diagnostic tools that our dealership maintains.
• Addressing issues early avoids secondary damage — for example, untreated misfires can ruin a catalytic converter, increasing repair costs substantially.
• Nalley Hyundai’s factory‑trained technicians provide accurate diagnosis and durable repairs that often deliver lower lifetime costs than piecemeal fixes from independent shops.