Our Check Engine Light Diagnostic Process
Full Service Diagnostic Testing moves from the dashboard warning to an identified cause and a repair recommendation. We don’t treat a stored code as a final diagnosis.
Retrieve the Stored Code
The onboard system stores diagnostic trouble codes when it detects a fault. A code points to the affected system, but it doesn’t necessarily identify a failed part.
Determine the Cause
Our technicians test the affected system to determine what triggered the code. Because one code can have several possible causes, diagnosis comes before we recommend a repair.
Review Your Repair Options
We explain our findings and provide repair recommendations supported by available Digital Vehicle Inspection photos. Repair work follows the identified issue and the option you approve.
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.
Steady vs. Flashing Check Engine Lights
A steady malfunction indicator lamp, commonly called the check engine light, generally points to a less urgent sensor or emissions-related issue. The vehicle still needs prompt inspection because the light alone can’t reveal the cause.
A flashing light is more serious. It can indicate an active engine misfire capable of causing rapid damage, so don’t continue driving the vehicle. Arrange an immediate inspection instead.
Check Engine Lights & Collin County Emissions Testing
Collin County requires an annual emissions inspection before vehicle registration can be renewed. Although Texas ended the statewide safety inspection requirement for most non-commercial vehicles on January 1, 2025, emissions inspections remain required in affected counties, including Collin County.
Gasoline-powered vehicles that are 2 to 24 years old and registered in a Texas emissions county receive an OBD-II test during the emissions inspection. OBD-II is the onboard diagnostic system that monitors engine and emissions performance. We tailor routine maintenance recommendations to help Murphy drivers address local emissions inspection requirements.
Common Causes of a Check Engine Light
The warning light can signal anything from a loose gas cap to an ignition or emissions fault. Because the dashboard indicator doesn’t distinguish among possible causes, the vehicle must be diagnosed.
Common triggers include:
- A loose or faulty gas cap
- A malfunctioning oxygen sensor
- A catalytic converter problem
- Faulty spark plugs, ignition coils, or wiring
- A damaged mass airflow sensor
- Poor-quality or incorrect fuel
These examples can’t diagnose a specific vehicle. Stored trouble codes and follow-up testing are needed to determine why the light came on.
Code Reading vs. Full Service Diagnostic Testing
A basic code reader retrieves diagnostic trouble codes stored by the onboard system. That information is useful, but a code identifies the affected system rather than proving which component should be replaced.
The same code can result from more than one underlying cause. Full Service Diagnostic Testing evaluates the reported fault before a repair is selected. At Christian Brothers Automotive Murphy, our ASE-certified technicians investigate the issue and develop repair recommendations.
Our free Digital Vehicle Inspection provides actual photos of the vehicle during servicing. These images add visual context to the diagnostic findings as you consider your repair options.
Schedule Check Engine Light Diagnosis in Murphy
Use our contact page to arrange check engine light diagnosis and receive clear information about the warning and recommended next steps.
Aaron Tharp owns and operates our Murphy location, and an owner-operator is on-site each day to provide direct access to leadership.
Complimentary shuttle service is available while your vehicle is being serviced. Work performed by our Murphy store is covered by the Nice Difference Warranty for 3 years or 36,000 miles, whichever occurs last.
Call (972) 535-5785 to schedule your check engine light service.
Vehicle Care After a Check Engine Light Diagnosis
A check engine light reflects a fault detected by the vehicle’s monitoring system. The resulting repair recommendation may involve an engine or emissions component, while brakes, tires, suspension, and other systems require separate evaluation.
Routine maintenance addresses scheduled care based on manufacturer service intervals and the vehicle’s condition. Our common services include Oil & Filter Change, Brakes, Scheduled Maintenance, and AC Services.
We also provide a free Courtesy Inspection covering major systems and components, including lights, brakes, suspension, tires, and the battery. This inspection can identify visible conditions beyond the fault that activated the malfunction indicator lamp.
For approved services, our Murphy location accepts Visa, AMEX, MasterCard, Discover, cash, Apple Pay, and financing.
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 have been a loyal customer of Christian Brothers Murphy TX, because of the staff and the exceptional service provided. They have always taken the time to explain the results of their mechanic’s findings and they work with me on reasonable repair co"
- John Dixon