Frequently Asked Questions

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

• Start with the fuel cap—on the 2021 Toyota Highlander Hybrid a loose or damaged gas cap is a common trigger and is quick to inspect and reseal.
• Check basic items you can see: low oil, coolant levels, visible fluid leaks, or a discharged 12V auxiliary battery in hybrids.
• If you can’t spot anything, bring the vehicle in for a professional scan—our factory-trained technicians use OEM scan tools designed for Toyota hybrid systems.
• Remember: any repairs covered under warranty must be performed at a certified dealership to preserve coverage and long-term savings.

How much does a check engine light diagnostic cost for a 2021 Toyota Highlander Hybrid?

• Diagnostics typically range modestly, and many dealerships provide a clear flat-fee diagnostic that often beats independent shop pricing when you factor in quality and warranty protection.
• At Nalley Toyota of Roswell, diagnostics are handled by factory-trained technicians using Toyota-specific tools—this reduces misdiagnosis and unnecessary expenses.
• We frequently cost less than independent shops when you include OEM parts, correct repairs, and retained warranty benefits—immediate savings and lower lifetime repair costs.
• If a repair is required and covered by warranty, it must be completed at a certified dealership to ensure full coverage and long-term protection.

What does it mean when the check engine light comes on in a 2021 Toyota Highlander Hybrid?

• The light indicates the vehicle’s onboard diagnostics detected an issue. In a hybrid, it can relate to emissions, engine, or hybrid-system components.
• Codes range from simple (loose gas cap) to serious (misfire, catalytic converter, hybrid battery or inverter concerns) and require a professional scan for accurate diagnosis.
• Our dealership performs a full diagnostic and explains immediate needs versus items that can wait, helping you manage cost and safety.
• For warranty-covered issues, repairs must be done at a certified dealership—this protects your coverage and ensures long-term savings with OEM parts and trained technicians.

What is the most common reason for check engine light on a 2021 Toyota Highlander Hybrid?

• The most frequent culprit is an emissions-related fault: loose gas cap, oxygen sensor, or EVAP system leak—these are common and often straightforward to fix.
• Other common causes include failing oxygen sensors, catalytic converter degradation, or occasional engine misfires; hybrids may also show hybrid-system alerts.
• Bringing the vehicle to Nalley Toyota of Roswell ensures an accurate OEM-level diagnosis and repair path that minimizes recurring costs and maximizes longevity.
• Repairs covered under warranty must be completed at a certified dealership to maintain coverage and deliver the best long-term value.

How long does a check engine light service take?

• Diagnostic scans for a 2021 Toyota Highlander Hybrid commonly take 30–60 minutes; more complex diagnostics or road testing may extend the time.
• Minor repairs (tightening gas cap, replacing a sensor) can often be completed the same day; more extensive repairs vary by part availability and complexity.
• Our dealership prioritizes efficient service with OEM parts and factory-trained technicians—this often yields faster, more reliable repairs and lower total cost than repeated independent shop visits.
• For warranty-covered work, having repairs done at a certified dealership preserves coverage and avoids delays or denials, providing both immediate and long-term savings.