Frequently Asked Questions

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

• Confirm safety: note any loss of power, unusual noises, or dashboard warnings and pull over if the vehicle feels unsafe.
• Check the gas cap: a loose or damaged cap is a common, inexpensive cause and can trigger an OBD-II code.
• Look for obvious signs: fluid leaks, burning smells, or extreme smoke indicate immediate service is needed.
• Record symptoms: engine behavior, recent fueling, or driving conditions helps diagnosis when you bring the vehicle to our service team.
• Remember warranty requirements: repairs covered under warranty must be performed by a certified dealership to preserve coverage.

How much does a check engine light diagnostic cost for a 2025 Lexus LS 500?

• Typical scan fee range: most dealerships charge a diagnostic fee that often falls between $80–$150 depending on inspection depth.
• Repair cost varies: simple fixes like a gas cap or sensor are low-cost; more extensive repairs like catalytic converters or engine work are higher.
• Dealership value: Nalley Lexus Roswell often costs less than independent shops when you factor in immediate, accurate diagnosis, genuine parts, and long-term savings from correct repairs.
• Warranty note: any repairs covered under warranty must be completed at a certified dealership to retain protection and ensure factory-trained technicians handle your vehicle.
• Transparent estimates: we provide clear write-ups and estimates before work begins, reducing surprises and protecting resale value.

What does it mean when the check engine light comes on in a 2025 Lexus LS 500?

• It signals the engine control unit has detected a fault — severity ranges from minor to urgent depending on the code.
• A steady light often indicates a non-emergency issue such as emissions, sensors, or EVAP system anomalies.
• A flashing light indicates a serious misfire or condition that can quickly damage the catalytic converter and requires immediate attention.
• Diagnostics are required to retrieve OBD-II codes and pinpoint the cause; our factory-trained technicians use Lexus-specific tools for accurate results.
• For warranty-covered faults, repairs must be performed at a certified dealership to maintain coverage and ensure proper software updates or calibrations.

How long does a check engine light service take?

• Initial scan and diagnostic typically take 30–60 minutes, depending on symptoms and code complexity.
• Simple repairs, such as replacing a sensor or tightening a gas cap, can often be completed within a few hours.
• Complex repairs—timing, catalytic converter, or engine diagnostics—may require additional time for parts and thorough testing.
• Nalley Lexus Roswell optimizes turnaround with factory-trained technicians, genuine parts, and efficient workflows to reduce downtime and long-term costs.
• If repairs are warranty-related, they must be performed at a certified dealership; we will provide a clear timeline and keep you updated throughout service.

What is the most common reason for check engine light on a 2025 Lexus LS 500?

• Common triggers include oxygen sensor issues, EVAP leaks, or misfires caused by spark plugs/coils.
• A loose or damaged gas cap is a frequent, inexpensive cause that often clears the code once corrected.
• Failing catalytic converters or multiple misfires can create more serious codes and higher repair costs if left unaddressed.
• Regular maintenance and factory service reduce the likelihood of these issues and protect performance and fuel efficiency.
• For warranty repairs, dealership service is required to preserve coverage; our technicians diagnose and repair to factory standards.