How Our Check Engine Light Service Works
We keep each stage clear, from scheduling and diagnosis through your approval and completed service.
Step 1: Schedule Your Appointment
Use our contact form or call the shop. When you bring in your vehicle, tell us what you’ve noticed, including whether the light is steady or flashing and whether the vehicle feels different.
Step 2: Diagnosis & Explanation
Our ASE-certified technicians perform Full Service Diagnostic Testing, reviewing stored codes alongside a mechanical and visual inspection of the affected systems. You receive a texted Digital Vehicle Inspection Report with photos and videos documenting the vehicle’s condition.
A service advisor reviews the findings and repair recommendations with you in plain language. We then provide a written estimate, and repairs don’t begin until you approve them.
Step 3: Approved Service
We complete or schedule the approved work based on parts availability and your availability. If the findings change during service, we contact you, explain the additional work, and obtain approval before proceeding. Once service is complete, you receive documentation of the work performed.
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.
How OBD-II Detects Vehicle Problems
On-board diagnostics, commonly called OBD-II, monitors the emissions control system and key engine components. Its diagnostic routines look for conditions that affect emissions performance, then store malfunction information as diagnostic trouble codes for a technician to retrieve.
The U.S. Environmental Protection Agency requires passenger cars and trucks from model year 1996 onward that are sold in the United States to meet OBD requirements. This technology can identify a fault before you notice a change in how the vehicle drives.
A stored code points technicians toward the system that detected the problem. It doesn’t confirm the failed part, which is why professional testing must continue beyond plugging in a scanner and reading a code.
Check Engine Lights & Arizona Emissions Testing
For Scottsdale drivers, an illuminated check engine light isn’t just a maintenance issue. Vehicles registered in Maricopa County are subject to Arizona emissions testing, and an active check engine light automatically results in a failed test regardless of the stored diagnostic code.
Clearing the code without correcting the fault won’t resolve the testing issue. Clearing diagnostic trouble codes also resets the OBD-II readiness monitors to “not ready.” Arizona emissions testing checks those monitors, and incomplete readiness monitors result in a failed test even when the warning light is off.
We provide emissions testing and can diagnose and repair issues after a vehicle fails. Completing a repair allows the vehicle’s onboard diagnostics to evaluate the affected components again during normal drive cycles, but a repair doesn’t guarantee a passing result or a specific readiness timeline.
Arizona Emissions Repair Assistance
Arizona’s Voluntary Vehicle Repair Program pays up to $900 toward eligible emissions-related repairs after a failed emissions test. Vehicle owners accepted into the program pay a $100 co-pay and must apply within 60 days of the failed test. Participation and assistance depend on the program’s eligibility requirements.
If your registration renewal is approaching and the check engine light is on, diagnose the underlying fault before taking the vehicle for its emissions test.
Is It Safe to Drive with the Check Engine Light On?
On-board diagnostics can detect problems before you notice unusual sounds, reduced performance, or other symptoms. Continuing to operate a vehicle with an illuminated check engine light can damage emissions-control components and increase the eventual repair cost.
A flashing check engine light requires immediate action because it signals a major active malfunction. Pull over safely, shut off the engine, and don’t continue driving until the problem has been inspected and repaired.
What Your Check Engine Light Is Telling You
The light’s behavior determines how urgently Scottsdale drivers should respond.
Check the Gas Cap First
A loose, damaged, or improperly tightened fuel cap can create an evaporative emissions fault that turns on the check engine light. Inspect the cap and tighten it completely. If a loose cap caused the fault and the seal is restored, the vehicle can turn off the light after several trips.
If the warning light remains on, schedule diagnostic service rather than repeatedly clearing the code. Another condition could be affecting the same emissions system.
Steady Light vs. Flashing Light
A steadily lit check engine light means the engine control unit has detected a fault that needs attention. The vehicle may drive normally, but the issue can still affect fuel efficiency and emissions output over time. Schedule a diagnostic appointment soon.
A flashing check engine light signals an active engine misfire. This serious condition can quickly damage the catalytic converter. Continued driving isn’t advised. Have the vehicle inspected immediately.
For a flashing light, arrange an immediate inspection at Christian Brothers Automotive South Scottsdale by calling (623) 343-1451 or using our contact form.
Common Causes of an Illuminated Check Engine Light
Stored fault codes can point to a wide range of possible causes. Some are minor, while others require prompt attention.
- Loose or faulty gas cap: A cap that isn’t sealing properly causes an evaporative emissions system leak and can trigger the light.
- Failing oxygen sensor: This common fault affects combustion timing and fuel economy.
- Mass airflow (MAF) sensor: A failing MAF sensor can cause rough idling, hesitation during acceleration, and reduced fuel efficiency.
- Worn or fouled spark plugs: Incomplete combustion from worn plugs can trigger misfires and illuminate the light.
- Catalytic converter degradation: This serious issue affects emissions output and can lead to costly damage if left unresolved.
- EGR valve, vacuum leaks, or battery connections: Each requires inspection to diagnose accurately.
Why an OBD-II Code Isn’t the Same As a Diagnosis
An OBD-II diagnostic scan retrieves the trouble codes stored by your vehicle’s engine control unit. Those codes identify which system registered a malfunction, not which specific component failed.
Take an oxygen sensor code as an example. That code can be triggered by the sensor itself, a wiring fault, an exhaust leak, or another sensor operating in the same circuit. Replacing the sensor based on the code alone, without further investigation, frequently results in a repair that doesn’t fix the actual problem.
Our Full Service Diagnostic Testing goes beyond basic OBD scanner codes. Technicians inspect the affected systems mechanically and visually, then deliver a detailed report on vehicle health before recommending any repair. That process supports an accurate fix, not a parts guess.
Your Local Christian Brothers Amenities
FAQs
-
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.
-
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.
-
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.
-
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.
-
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.
-
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
-
"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.