2018 Mercedes-Benz S-Class Check Engine Light

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Frequently Asked Questions

Frequently Asked Questions

What does it mean when the check engine light comes on in a 2018 Mercedes-Benz S-Class?

  • It signals that the vehicle’s onboard diagnostics (OBD-II) has detected a fault. Faults range from minor emissions issues to sensor failures or engine management problems.
  • At Mercedes-Benz of Lynnfield in Lynnfield, MA, our factory-trained technicians use Mercedes-grade diagnostic tools to identify the exact code and its root cause—fast and accurately.
  • Repairing issues promptly at our dealership often costs less than independent shops when you account for lasting OEM parts, certified repairs, and the long-term savings from avoiding secondary damage.
  • Many warranty-covered repairs must be completed at a certified dealership to preserve coverage; our service team can confirm eligibility and advise next steps.
  • To get an accurate diagnosis and recommended repairs, schedule service or check current offers on our service specials.

How long does a check engine light service take?

  • Diagnostics typically take 30–90 minutes depending on symptoms and whether a road test or extended data logging is required.
  • Minor fixes such as sensor replacements or loose gas cap corrections can often be completed the same day; more complex repairs may require parts and a brief return visit.
  • Mercedes-Benz of Lynnfield prioritizes quick turnaround with courtesy amenities and transparent timelines—our advisors keep you informed at every step.
  • We offer service financing so you can get service now and pay later, reducing downtime and letting you focus on driving safely.
  • To confirm availability and timing, schedule service online or call our service team at the contact details on our main site.

How much does a check engine light diagnostic cost for a 2018 Mercedes-Benz S-Class?

  • Diagnostics at Mercedes-Benz of Lynnfield start as low as $99.75 for a check engine light evaluation. This reflects our transparent pricing and value-driven approach.
  • Choosing our dealership often delivers immediate savings and better long-term value compared with many independent shops thanks to OEM parts, certified technicians, and accurate repairs that prevent repeat visits.
  • If additional repairs are needed, we provide clear estimates and available service specials to help reduce out-of-pocket costs.
  • Remember: warranty-covered work must be performed at a certified dealer to preserve coverage—our team will verify warranty status before any work begins.
  • Book a convenient appointment now by clicking to schedule service and ask our advisors about service financing options to spread your payments.

What is the most common reason for check engine light on a 2018 Mercedes-Benz S-Class?

  • Common causes include oxygen sensor faults, catalytic converter efficiency issues, loose or faulty gas caps, and mass airflow or camshaft/crankshaft sensor errors.
  • Even seemingly small issues can escalate into costly repairs if ignored; our certified technicians in Lynnfield diagnose and address the underlying cause to protect performance and fuel economy.
  • Bringing your vehicle to Mercedes-Benz of Lynnfield ensures genuine Mercedes parts and factory diagnostic procedures—this reduces the risk of incorrect repairs and costly follow-ups.
  • We highlight both immediate savings and long-term benefits of dealership service, including improved resale value and lower lifetime maintenance costs.
  • To have a technician examine your vehicle, schedule service online or view available service specials.

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

  • Start with the basics: ensure the gas cap is tightened; a loose or damaged fuel cap is a common trigger and often an easy fix.
  • If the light persists, avoid long trips and bring the vehicle to Mercedes-Benz of Lynnfield for a professional scan—our technicians will read codes and run targeted tests.
  • We emphasize dealership transparency: you’ll receive a clear diagnosis, repair options, and an estimate before any work begins. Warranty-covered repairs must be completed at a certified dealer to remain valid.
  • Take advantage of our service financing to address issues immediately without delaying needed repairs, saving time and preventing secondary damage.
  • When you’re ready, schedule appointment online or check our service specials for savings opportunities.

Check Engine Light Flashing

A flashing check engine light in a 2018 Mercedes-Benz S-Class typically signals a severe misfire or a condition that can rapidly damage the catalytic converter and other emissions components. When faced with a flashing light, prompt action matters: continuing to drive can multiply repair costs and compromise drivability. At Mercedes-Benz of Lynnfield in Lynnfield, MA, our certified technicians prioritize immediate diagnostics and safe towing options when needed. We use OEM-level scanners and data logging to capture intermittent faults and execute precise repairs—whether it’s an ignition coil, spark plug, fuel injector, or a more complex engine management issue. Choosing our dealership gives you transparent estimates, factory parts, and technician expertise that reduce the risk of repeat failures. We also offer convenient customer amenities and service financing so you can take care of urgent repairs now and manage payments over time. Be proactive—review our current service specials and schedule service online to secure prompt attention and protect your S-Class from costly downstream damage.

2018 Mercedes-Benz S-Class Check Engine Light Reset

Resetting the check engine light on a 2018 Mercedes-Benz S-Class might seem simple, but a true resolution requires an accurate fix. A reset without addressing the root cause can erase codes temporarily while the underlying problem persists, leading to further damage or safety risks. At Mercedes-Benz of Lynnfield, our approach combines a full diagnostic scan with verification testing after the repair so the light stays off for good. We explain why dealership service matters: OEM parts, factory calibration, certified technicians, and proper software updates ensure lasting results. Warranty claims require certified dealership repair to remain valid—our service advisors will confirm coverage and explain warranty benefits. We also provide clear pricing, and often our total cost is lower than independent alternatives once you factor in lasting repairs and OEM warranties. Don’t forget to check our service specials for discounts; when ready, schedule appointment online to book expert attention and preserve vehicle value.

2018 Mercedes-Benz S-Class Check Engine Light Codes

Common check engine light codes for a 2018 Mercedes-Benz S-Class include P0300 (random/multiple cylinder misfire), P0420 (catalyst system efficiency below threshold), P0171/P0174 (fuel trim/system too lean), and various sensor codes for oxygen, mass airflow, or cam/crank position. Each code carries cost implications if left unresolved: misfires can lead to catalytic converter failure and engine damage; fuel-trim issues reduce fuel economy and increase emissions; sensor failures may cause drivability problems and poor performance. At Mercedes-Benz of Lynnfield, our technicians in Lynnfield, MA, diagnose codes clearly, present repair options, and outline immediate and long-term savings—like improved MPG and avoided major component replacement. We back work with OEM parts and certify repairs to protect warranties and resale value. To help owners save, we publish timely service specials and offer service financing so repairs can start immediately without financial delay. If you see a code or an illuminated engine light, schedule service with our team for a precise diagnosis and a transparent repair plan.