Frequently Asked Questions

What is the most common reason for check engine light on a 2025 Volkswagen Jetta GLI?

• Common causes include misfires (ignition or fuel), oxygen sensor failure, catalytic converter issues, and small evaporative emissions leaks.
• Many faults begin as inexpensive items — for example, a loose gas cap or a failing O2 sensor — but can escalate if ignored.
• Early diagnosis at Nalley Volkswagen of Alpharetta helps avoid costly repairs later and preserves factory warranties.
• Our factory-trained technicians use Volkswagen-specific scan tools to pinpoint causes quickly and accurately.

What does it mean when the check engine light comes on in a 2025 Volkswagen Jetta GLI?

• It signals a stored fault code from the engine, emissions, or powertrain systems — anything from a minor sensor issue to a serious misfire.
• A steady light usually indicates a condition that should be checked soon; a flashing light means immediate attention is required.
• Bring your vehicle to Nalley Volkswagen of Alpharetta so our technicians can read the exact code and recommend the correct repair.
• Repairs covered under warranty must be performed at a certified dealership to remain valid.

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

• Start with easy checks: confirm the gas cap is tight and undamaged — an evap leak is a common trigger.
• Listen and note drivability: rough idle, stalling, or reduced power are clues that help technicians prioritize diagnostics.
• If the light is flashing, stop driving and have the vehicle inspected immediately to prevent engine or catalytic converter damage.
• Schedule a diagnostic at our service center via https://www.nalleyvw.com/service/schedule-appointment.htm for a fast, accurate evaluation.

How much does a check engine light diagnostic cost for a 2025 Volkswagen Jetta GLI?

• Diagnostic fees vary; a dealership diagnostic provides a vehicle-specific scan, code interpretation, and recommended repair plan from factory-trained technicians.
• Nalley Volkswagen of Alpharetta often costs less than independent shops when you factor immediate fixes, accurate diagnosis, and long-term savings from correct repairs.
• If a repair is covered under warranty, it must be completed at a certified dealership to preserve coverage and avoid future expense.
• Check current offers and service specials at https://www.nalleyvw.com/specials/service.htm or book at https://www.nalleyvw.com/service/schedule-appointment.htm.

How long does a check engine light service take?

• Simple diagnostics and minor repairs (tightening a gas cap, replacing a sensor) may take under an hour; more complex diagnostics or repairs can take several hours or a day.
• Our factory scan and inspection process is efficient — we prioritize accurate fixes that avoid repeat visits and protect long-term value.
• Time estimates are provided after initial diagnosis; scheduling is available at https://www.nalleyvw.com/service/schedule-appointment.htm to minimize wait time.
• Using a certified dealer often reduces total downtime because we have OEM parts, technical resources, and warranty-backed repairs on site.