What Full Service Diagnostic Testing Involves
Our diagnostic process goes beyond retrieving a code from the vehicle’s onboard computer. A stored code identifies the system in which the vehicle detected a fault, but it doesn’t identify the failed part or establish the required repair.
We perform further diagnosis to identify the root cause before discussing the vehicle’s repair needs. During service, we also provide a free digital vehicle inspection with actual photos of your vehicle. Those images document visible findings and provide useful context for the information we share.
Once we complete the evaluation, we explain the service needs in understandable terms. You can ask questions about the findings and underlying issue instead of relying on a code description alone.
1. Schedule Your Appointment
Whether scheduling online or over the phone be sure and let us know what you're experiencing so we can provide fast and accurate service advice.
2. Diagnostics and Inspections
Drop off your vehicle and the shop will get to work with inspections and diagnostics using the same equipment as the manufacturers to determine issues and next steps.
3. Digital Vehicle Inspection Report and Estimate
Following the diagnosis we will text you a digital vehicle inspection report, containing pictures and videos of our findings and recommendations.
4. Review and Approval
A service advisor will reach out to walk you through the findings and recommendations to determine how you would like to proceed, or you can approve work directly in your DVI.
5. Work Performed or Scheduled
Most work can be completed immediately, or scheduled based on parts and customer availability.
Vehicle Systems Connected to Check Engine Light Concerns
A check engine light can relate to different areas of a vehicle, which is why an accurate evaluation matters. Popular services at our Schertz location include:
Our free Courtesy Inspection is separate from check engine light diagnostics. It provides a broader review of major vehicle systems and components while your vehicle is with us.
The Courtesy Inspection includes:
- Exterior and warning lights
- Brakes
- Suspension
- Tires
- Battery
This inspection provides a broader view of the vehicle’s condition, while diagnostic testing focuses on the reason for the check engine warning.
Repair Costs Depend on the Diagnosed Cause
A stored code alone can’t establish how much a repair may cost. Several conditions within the same system can produce the same code, and each may require different work. The necessary repair depends on the root cause found through diagnosis.
When repairs are performed at Christian Brothers Automotive Schertz, our 3-year or 36,000-mile warranty applies, whichever occurs last. This coverage reflects our commitment to the workmanship provided after the underlying problem has been identified.
Emissions Inspections & Registration Requirements
Schertz spans multiple counties, so emissions requirements depend on the county in which a vehicle is registered. Beginning November 1, 2026, enhanced annual emissions inspections apply to eligible vehicles registered in Bexar County, which is subject to the new program. A covered vehicle must pass the required inspection before its annual registration can be renewed.
The requirement applies to gasoline-powered vehicles that are 2 through 24 model years old. The inspection reads information from the vehicle’s onboard diagnostic system. An illuminated check engine light results in an automatic emissions inspection failure.
Electric vehicles, diesel vehicles, and motorcycles aren’t subject to this emissions inspection requirement. The maximum inspection fee is $18.50. Because eligibility follows the vehicle’s county of registration rather than where it’s driven, owners should confirm which requirement applies to their registration.
What Steady & Flashing Check Engine Lights Mean
A steady check engine light indicates a problem that should be checked soon, but it generally doesn’t require you to stop the vehicle immediately. A flashing light is more urgent. It can indicate an active misfire, which means the engine isn’t burning fuel correctly in one or more cylinders and requires immediate attention.
Common causes include a loose gas cap, poor-quality fuel, worn spark plugs, faulty ignition coils, or an oxygen sensor problem. Engine and transmission concerns may also trigger the warning.
Other possible sources include mass airflow sensor damage and catalytic converter problems. Because these issues vary considerably in scope, the warning light or stored code can’t provide a reliable diagnosis by itself.
Schedule Check Engine Light Diagnostics in Schertz
We identify the reason for the warning and explain what we find in direct, understandable terms. If you need to continue with your day while the vehicle is being serviced, complimentary shuttle service is available for customer pickup and drop-off.
Our contact form provides another convenient way to request service based on an informed evaluation rather than a dashboard light or code alone.
Call (210) 702-3215 to schedule check engine light diagnostics with Christian Brothers Automotive Schertz.
Why a Scanner Code Isn’t a Complete Diagnosis
Standardized codes are stored when a vehicle detects operation outside an expected range. A code directs attention to an affected system or condition, but it doesn’t prove that a named component has failed.
Multiple faults can trigger the same code. For example, a code associated with a sensor may originate from the sensor, its electrical circuit, or another condition affecting the readings it reports. Replacing a component based only on a scanner result can overlook the actual source.
Our check engine light diagnostics go beyond basic scanner codes. We read the stored information and perform further evaluation to identify the root cause and the repair the vehicle needs.
Your Local Christian Brothers Amenities
FAQs
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Q. "What is the difference between a steadily lit and a flashing check engine light?"A steadily lit light means that a sensor is sending a signal to your vehicle's computer that something is wrong or it could simply mean that the sensor is out. If your check engine light is flashing, however, that means there is a serious issue and you should stop driving immediately.
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Q. "Why is my check engine light on but nothing seems to be wrong with my vehicle?"If nothing within your vehicle stands out, then it is possible that it is just a minor issue such as a loose gas cap or a bad O2 sensor. It is still recommended to see a mechanic if the light doesn't disappear to check for any larger issues.
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Q. "Do you offer a warranty?"As part of our Nice difference.® commitment to providing our customers the best auto service experience possible, we also offer a3-year/36,000-mile warranty on all the work that we do. We offer this warranty at every Christian Brothers Automotive nationwide, and it will be honored at any location, regardless of which branch did the initial work.
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Q. "Can you provide service under my extended warranty?"Yes. At Christian Brothers Automotive, we work with all major extended warranty providers to make needed repairs for our customers. If you have an extended warranty, you can discuss your carrier with our team when scheduling an appointment and confirm that the work will be covered. You can find a partial list of the extended warranty companies we work with here.
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Q. "What to do if your check engine light turns on?"We recommend heading to your local auto shop as soon as you are able. This is typically a sign that there is an abnormality within your engine.
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Q. "Is it safe to drive your car when the check engine light is on?"It depends. If you are experiencing other noticeable issues with your vehicle, it may be best to pull over. Otherwise, it is typically okay to drive to your local auto shop. You will want to get this checked sooner rather than later to avoid being stranded with a broken-down car.
Have more Questions?
Our friendly auto service experts have the answers.
Call your local Christian Brothers Automotive car shop today
Hear What Our Customers Had to Say About Us
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"I liked the customer service and going above and beyond to make sure I was comfortable while waiting in the store for my vehicle work to be done, specifically being offered a nice hot coffee with creamer."
- J.L.