Frequently Asked Questions

What does it mean when the check engine light comes on in a 2026 BMW 8 Series Gran Coupe 840i?

• It signals the vehicle’s onboard diagnostics detected an issue — anything from a loose gas cap to an emissions sensor or an engine misfire. In Decatur, Nalley BMW of Decatur diagnoses the root cause quickly using OEM scanners and factory procedures.
• Choosing our dealership often costs less than independent shops when you factor in correct diagnosis, long-term repair accuracy, and warranty coverage that avoids repeat visits.
• Warranty repairs must be performed at a certified dealership to preserve coverage; our BMW-certified technicians complete those repairs precisely and document them for future service needs.
• We offer service financing so you can get service now and pay later. To book, please schedule service online or check current service specials.

How long does a check engine light service take?

• Diagnostics typically take 30–90 minutes depending on codes and inspection complexity. If further repairs are required, our service advisors provide transparent timelines and cost estimates.
• Nalley BMW of Decatur prioritizes speed without sacrificing quality — OEM parts, factory tools, and trained technicians reduce rework and deliver faster long-term results.
• We recommend scheduling so we can align parts and technicians. Use this link to schedule appointment and review current service specials.

How much does a check engine light diagnostic cost for a 2026 BMW 8 Series Gran Coupe 840i?

• Diagnostic fees vary, but Nalley BMW of Decatur provides competitive pricing and clear estimates up front. Our pricing often delivers immediate and long-term savings compared with repeated, uncertain repairs from non-certified shops.
• If your vehicle is under warranty, covered repairs must be completed at a certified dealership to retain coverage — our advisors will confirm warranty eligibility before work begins.
• Ask about service financing and current service specials when you schedule service.

What is the most common reason for check engine light on a 2026 BMW 8 Series Gran Coupe 840i?

• Common causes include oxygen sensor faults, catalytic converter issues, ignition misfires, or turbocharger-related sensors. Early diagnosis avoids expensive downstream repairs and preserves performance.
• At Nalley BMW of Decatur we use factory-grade tools to isolate issues quickly and recommend OEM repairs that protect vehicle longevity and resale value.
• Taking care of issues promptly saves money long term; schedule an inspection via schedule appointment and review our service specials.

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

• Safely check for simple causes first (e.g., loose gas cap). If the light persists or is flashing, stop driving and bring the vehicle to Nalley BMW of Decatur for immediate attention.
• A flashing check engine light can indicate active misfires that may damage the catalytic converter — certified diagnosis prevents larger bills later.
• We offer service financing and transparent estimates to get you back on the road quickly. To act now, schedule service or view service specials.