Frequently Asked Questions

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

• Confirm fuel level and tighten the gas cap — a loose cap is a common, simple fix that can extinguish the light.
• Look for additional dashboard messages or unusual symptoms (smell, noise, loss of power) that indicate severity.
• Record when the light came on and any driving conditions; this helps technicians diagnose faster.
• For any repairs covered under warranty, remember they must be performed at a certified dealership to remain valid.
• If the light is flashing or symptoms are severe, stop driving and bring the vehicle to our service center immediately.

How much does a check engine light diagnostic cost for a 2015 Toyota Prius One?

• Typical diagnostic fees range from approximately $99 to $149, depending on inspection depth and test drives required.
• At Nalley Toyota of Roswell we provide clear estimates and explain repair options so you see immediate and long-term savings.
• Because we use factory-grade tools and trained technicians, many repairs are handled more efficiently and often cost less than independent shops.
• Any repairs covered under warranty must be performed at a certified dealership to preserve coverage and ensure quality work.
• Diagnostics can reveal simple fixes or prevent more costly future failures by identifying issues early.

What does it mean when the check engine light comes on in a 2015 Toyota Prius One?

• The light indicates the vehicle’s onboard computer has detected an emissions, fuel, ignition, or sensor fault.
• Common causes include oxygen sensors, catalytic converter concerns, ignition misfires, or fuel system irregularities.
• Many issues are benign at first but can lead to reduced fuel economy, higher emissions, or component damage if not addressed.
• Bringing your Prius to a certified dealership ensures accurate code reading, proper repairs, and warranty compliance.
• Early diagnostics with factory tools help minimize repair costs and protect long-term vehicle value.

What is the most common reason for check engine light on a 2015 Toyota Prius One?

• A loose or faulty gas cap remains one of the easiest and most common causes of the check engine light.
• Other frequent reasons include oxygen sensor failure, ignition misfires, and evaporative emissions system faults.
• Left unresolved, these faults can lower fuel economy, raise emissions, and lead to more expensive repairs later.
• Our dealership provides thorough diagnostics to distinguish simple fixes from issues needing certified repairs.
• Warranty-covered repairs must be done at a certified dealership to ensure coverage and correct parts installation.

How long does a check engine light service take?

• Diagnostics typically take 30–90 minutes depending on drive tests and intermittent code behavior.
• Simple repairs (gas cap, sensor replacement) can often be completed the same day; more involved repairs vary by parts and scope.
• At Nalley Toyota of Roswell our factory-trained technicians use precise processes to minimize downtime and get you back on the road quickly.
• We prioritize warranty compliance and use OEM parts so repairs are reliable and provide long-term savings versus repeated shop visits.
• If urgent, we’ll advise whether immediate towing to the dealership is required to prevent further damage.