Frequently Asked Questions

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

• Look for dashboard messages or warnings—modern trucks like the 2024 GMC Sierra 3500HD often show supplemental alerts (DEF low, DPF regen needed, low oil) that point to the issue.
• Check fluid levels that affect emissions systems: DEF and engine oil; low DEF commonly triggers emissions faults on diesel trucks.
• Note driving symptoms (loss of power, rough idle, smoke) and towing load; these clues help technicians prioritize diagnostics.
• If the light is flashing, stop driving and have the vehicle towed to a certified service center to avoid further damage.
• Bring your truck to Coggin Buick/GMC of Orange Park—our factory-trained technicians will run a full scan and advise next steps; warranty-covered repairs must be completed at a certified dealership.

How much does a check engine light diagnostic cost for a 2024 GMC Sierra 3500HD?

• Diagnostic scan fees typically range from modest flat fees up to about $150–$200 depending on scope; at our dealership the fee is often credited toward repairs when performed here.
• Minor fixes like sensor replacements can be inexpensive, while turbo, injector, or DPF repairs are higher-cost—our technicians provide clear estimates before work begins.
• Coggin Buick/GMC of Orange Park often costs less than independent shops because we combine diagnostic accuracy, OEM parts and efficient factory processes to lower immediate and long-term expenses.
• Remember: repairs covered under warranty must be done at a certified dealership to remain valid—our service team preserves warranty protection and future resale value.
• We recommend scheduling a diagnostic at our service center so you get an exact, written estimate and transparent timeline.

How long does a check engine light service take?

• Simple diagnostics can take 30–90 minutes; many sensor-related repairs are completed the same day.
• Complex repairs—DPF cleaning, injector work, turbo replacement or emissions component sourcing—may require several hours to multiple days, depending on parts availability.
• At Coggin Buick/GMC of Orange Park our factory-trained technicians and GM tools speed diagnosis and repair, often reducing total downtime compared with independent shops.
• We communicate realistic timelines and offer loaner or shuttle options when extended service is required to minimize disruption.
• If a repair is covered by warranty, having work done at a certified dealership ensures timely authorization and proper documentation.

What does it mean when the check engine light comes on in a 2024 GMC Sierra 3500HD?

• The light signals a stored trouble code from the engine or emissions control system; on diesel trucks it commonly relates to DPF, DEF, NOx sensors, turbochargers, fuel injectors, or emissions dosing systems.
• It can range from a simple sensor fault to a condition that affects performance or towing capability—diagnostic data and freeze-frame information determine severity.
• Ignoring the light risks reduced fuel economy, compromised towing capacity, or progressive damage to high-cost components like the turbo or DPF.
• Bring the 2024 GMC Sierra 3500HD to Coggin Buick/GMC of Orange Park for a full diagnostic and professional repair plan; warranty-covered repairs must be performed at a certified dealership.

What is the most common reason for check engine light on a 2024 GMC Sierra 3500HD?

• On diesel heavy-duty trucks the most frequent triggers are aftertreatment and emissions sensors—DPF regeneration failures, DEF dosing faults, or NOx/pressure sensor errors.
• Other common causes include turbocharger boost issues, fuel injector faults, or glow plug/injection system anomalies that affect combustion.
• Many of these issues can be caught early with proper diagnostics; addressing them promptly avoids major part failures and higher repair costs.
• Coggin Buick/GMC of Orange Park uses GM-specific tools to identify root causes quickly and explain cost-effective repair options that often save more than independent shops, while protecting warranty coverage.