12 Apr Check Engine Light
Demystifying The Check Engine Light Myth
Any mechanic who has seen a check engine light knows that it could indicate anything from a simple repair to a complex diagnostic issue. As an automotive professional, I have over 25 years of experience as a technician, service adviser, and service manager. During that time, the one thing that I found the most difficult to communicate to customers was diagnostic time related to a check engine light. To make matters worse, customers often compare the service they receive at a quality shop with the deceiving convenience of parts stores, cheap shops, and misleading automotive chain repair retailers (Midas, AAMCO). Such establishments typically use a generic handheld code puller to pull the code/s related to a check engine light and sell repairs and parts on the spot without performing any diagnosis. Customers who then install the part and feel they have resolved the issue may ask, “Who needs a technician?!” only to find out that the problem isn’t solved. Don’t you wish it was that easy! It would take a lot of the cost and stress out of auto repair. Diagnosing computer-controlled vehicles can be costly for the consumer as well as the shop.
In order to demystify the check engine light scenario and the diagnostics associated with it, let us start with a breakdown of what diagnosing a check engine light on a computer-controlled vehicle looks like at a quality repair facility:
1.) Trained Service Advisor:
This is your point-person for the interaction. A repair order will need to be written, the vehicle properly identified, and the problem effectively communicated to the technician. The repair order is a legally binding agreement written by a service advisor who is trained in the best customer service practices. An untrained advisor is likely to miscommunicate some part of the process that can lead to mistrust, repairs taking longer than expected, or charges that weren’t properly communicated. A trained service advisor is a professional. Having someone on staff at the caliber needed to ensure clarity and communicate expectations to both parties comes at a cost.
2.) Trained (Ideally ASE Certified) Technician:
If you were sick, would you want a medical student or an inexperienced doctor diagnosing your health issue? Proper automotive professional training and quality equipment is expensive. Professional auto technicians undergo formal education, continuous ongoing training, and purchase their own professional quality tools. These costs and time commitments are comparable to those incurred by someone who has a more traditional college degree.
3.) Good Quality Computer Diagnostic Tool (Scan Tool):
A scan tool is used to interface with your vehicle’s computer systems. It is capable of “pulling a code” related to your check engine light. Pulling a code is only a starting point. These scan tools range from basic code readers to advanced diagnostic platforms. Advanced scan tools, such as ones from OEM Car manufacturers can cost upwards of $25,000. The shop generally incurs this cost as well as the cost of training the staff to properly use the advanced functions of this tool. This tool in NO WAY tells you directly what is wrong with the vehicle. It provides codes, data, and other information for the technician to interpret in order to get started with diagnosing the problem. The technician must use his knowledge to trace down and diagnose the issue with the vehicle.
4.) Example of Common Check Engine Light Scenario:
Good equipment and top-level technicians are very costly. Let’s take a look at what happens at a parts store (or with an inexperienced, untrained mechanic). You get your “code pulled” and the code points to a problem in the O2 bank 1 sensor 2. The parts store sells you an O2 sensor and the cost of this sensor is generally $90-$800, depending on the sensor and the vehicle it is designed for. The sensor is installed and the check engine light is still on (electronic parts are generally NOT returnable). Why is the check engine light still on??? The code said it was the O2 sensor.
Experienced and properly trained mechanics know that an O2 sensor reads the amount of oxygen in the exhaust system, which is an indication of the air/fuel ratio mixture. The goal of the sensor is to help the engine run as efficiently as possible and also to produce as few emissions as possible. The code is actually an indication of a problem with the ratio of air and fuel and it is telling you that sensor readings are out of range. This problem could be an indication of a failing O2 sensor; but in most cases it is the detection of a problem with another related system. There is no guessing in these situations, you need a professional scan tool AND a trained technician to completely diagnose and repair the problem. After all, you wouldn’t get an MRI without having a trained doctor to interpret the results.
5.) Summing it all up:
When a patient goes to the doctor, the doctor doesn’t tell him or her what is wrong for free. Nor does the patient ask a pharmacist to diagnose a medical condition. Parts stores or inexperienced mechanics shouldn’t diagnose a computer-controlled vehicle. In providing a professional diagnosis, a quality shop will have invested in the staff and tools needed to provide accuracy, save time, frustration, and, in the long run, money. All of these things are costly and necessary for a fair customer-to-shop interaction. Quality shops who build long lasting relationships with clients help them understand why paying a diagnostic charge is fair and necessary. When the “check engine light” illuminates, it is important for the you to communicate everything that you can recall to the service adviser. This includes when and where you first noticed the check engine light illuminate. Be sure to inform the Service Adviser of the driving conditions at the time of occurrence and anything you can recall about differences in the car’s behavior. Remember: the more information you can give the service staff, the better your chances of having the check engine light issue solved quickly and save you diagnosis time.
– Quality and Competence –
At Rennwerks, we take pride in caring for you, and we are invigorated by the opportunity to provide you competent and comprehensive automotive repair services. We are the leading repair, tuning, and race facility in the areas of Campbell, Los Gatos, Saratoga, Cupertino, San Jose, Los Altos, Santa Clara, Sunnyvale, Willow Glen, Evergreen, Rose Garden, Cambrian, and Almaden. We provide you personalized, detailed, and friendly service. Our relationships are built on trust, communication, integrity, and commitment to you.
We have the know-how to keep your vehicle top-notch condition. At Sprint Motorsports we provide the best quality OEM parts. Give your car the proper love and car that it needs by experts with the proper tooling and equipment and avoid using the ill-equipped mobile mechanics. We have expert trained staff that undergo constant training and education to stay up to date with the latest industry technology. We have dealership level equipment. Give us a call!
We stand behind our work with a 2 year warranty on repair work!!!*
To schedule an appointment to have your check engine light issue resolved, please contact firstname.lastname@example.org or 408-831-3730. We welcome you to stop by our shop at 2099 S 10th St Unit 40, San Jose, Ca 95112. If you have any questions about your auto’s performance or maintenance, don’t be shy and ask our friendly staff for assistance.