Frequently Asked Questions

What does it mean when the check engine light comes on in a 2026 Mercedes-Benz GLS?

• It signals an emissions, engine, or sensor fault detected by the vehicle's onboard computer — anything from a loose gas cap to a failed catalytic converter.
• At Mercedes-Benz of Chesterfield our factory-trained technicians use OEM scanners to identify the exact code, giving you clear options and repair timelines.
• Choosing our dealership often costs less than independent shops because we diagnose accurately the first time, avoid unnecessary repairs, and protect long-term value with OEM parts.
• Repairs covered under warranty must be completed at a certified dealership; we also offer service financing so you can get repairs now and pay later.
• To get a fast, accurate evaluation, schedule service online or review our current service specials.

How long does a check engine light service take?

• Diagnostics typically take 30–90 minutes depending on codes and road-test requirements; many appointments are completed the same day.
• Our service center in Chesterfield, MO prioritizes quick turnarounds, clear estimates, and constant updates so you’re never left waiting.
• Because we use OEM tools and parts, repairs often require fewer follow-ups, delivering both immediate savings and lower lifetime ownership costs.
• We offer convenient amenities while you wait and flexible financing to make necessary repairs manageable.
• Ready to book? Use our online form to schedule service or check current service specials for savings.

How much does a check engine light diagnostic cost for a 2026 Mercedes-Benz GLS?

• Diagnostic fees vary, but our transparent pricing and expert diagnosis often save you money versus independent shops by preventing misdiagnosis and repeated labor.
• We provide a clear estimate before any repair and highlight immediate and long-term savings from using OEM parts and certified technicians.
• Warranty-covered repairs must be performed at a certified dealership to retain coverage — our certified team protects your investment.
• If you need flexible payment options, ask about our service financing so you can address the issue now and pay over time.
• To get an exact price and appointment, schedule service online and view available service specials.

What is the most common reason for check engine light on a 2026 Mercedes-Benz GLS?

• Common causes include faulty oxygen sensors, loose or damaged gas caps, ignition coil failures, or catalytic converter issues — each has different cost and urgency.
• Addressing codes promptly at Mercedes-Benz of Chesterfield prevents escalation to more expensive repairs and maintains fuel efficiency and emissions compliance.
• We prioritize OEM repairs that preserve vehicle longevity; warranty claims and parts replacements performed here keep coverage intact.
• Take advantage of our transparent estimates and ask about financing options to manage unexpected costs without delay.
• Book a diagnostic appointment today by clicking to schedule service or browse our service specials.

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

• Simple checks include ensuring the gas cap is tight and inspecting for obvious leaks — but avoid guessing; modern systems require OEM-level diagnostics.
• Our certified technicians at Mercedes-Benz of Chesterfield scan vehicle codes with factory tools to pinpoint the issue and recommend the most cost-effective repair.
• Prompt, correct repair at a certified dealership often saves money immediately and over time by avoiding repeated labor and part replacements.
• We honor warranty requirements for covered repairs and offer service financing if you need help managing the cost.
• To get a professional inspection, schedule appointment with our service team or view current service specials.