Why is my check engine light on?
I hear this a-lot, and the real answer is only the car knows.
If the light is on steady and the vehicle seems to be driving fine you most likely have plenty of time to get to the garage to have it checked out. If however the light is flashing then serious damage could occur to the catalytic converter. In this instance you want to get to the garage as soon as possible.
The reason for the light being on could be simply a loose gas cap or a sensor going bad. In the old days everyone blamed the oxygen sensor every time the light came on, but engine management systems have progressed so much and become so complex that guessing is a bad idea. The light simply means that the computer see's a parameter out of range.
At Stroudwater Tire & Auto we do a Free check engine light scan. This is the first step in diagnosing what the problem might be. Sometimes it's simple and can be solved easily. Other times the problem will require more involved diagnostics. We are fully equipped to diagnose most any problem whether mechanical or electrical or electronic.
So don't let that check engine light scare you, come on in and see us for a free check engine light scan today.
What is a Diagnostic?
Just what is involved with the diagnostic charge when getting your vehicle repaired? Many people are confused about this.
Many people believe that the car is plugged into a diagnostic machine and the machine prints out everything that is wrong with the vehicle. This is not correct. A thorough diagnostic procedure involves inputs from several different sources. The diagnostic machine is only one tool and not the final judge. The better the diagnostic equipment, the more accurate the diagnostic is. As you can see from our diagnostic equipment page, there are many different types of equipment available.
On 1996 and later vehicles, the vehicles own on board computer provides significant amount of data, but not answers. On 1995 and earlier vehicles there is very limited data available through the computer.
Generally the first step is to connect the diagnostic scanner to the vehicle and look for any malfunction codes that are present. The technician then looks at raw data streaming through the vehicles computer if available. Frequently the malfunction code present indicates the symptom and is not the root of the solution. The technician's training, experience, and inherent trouble shooting skills now become very important.
Frequently the next step involves driving the vehicle. With some preliminary information, the technician is now prepared to pay particular attention to specific symptoms, sounds, and characteristics related to the customers concern.
No vehicle is perfect. Each vehicle model and year has characteristic problems. The vehicle manufacturer's publish Technical Service Bulletins (TSB's) describing common problems and their symptoms. A good technician will check the bulletins for your vehicle to see if the problem is similar to one of those described. The better diagnostic computers also have detailed troubleshooting information and common faults that the manufacturer's do not report. This information is updated periodically, either quarterly or at least annually.
The next step is to follow diagnostic trouble shooting diagrams. These diagrams indicate tests to be performed, and based upon the result, additional tests or conclusions. Some diagnostic procedures are very short, others go on for several pages. The technician's knowledge and experience guide him on where to begin in the troubleshooting procedure.
The last step is to test the suspected bad part isolated from the rest of the system. This is not always possible, but is desirable if practical. With all the information that is available, the knowledge, experience and skill of the technician becomes more important to sort through what is pertinent to the current problem, and what is extraneous.
There is always a charge for diagnostic. Most shops in this area have charges between $80-100 to start. This includes connecting the diagnostic equipment, reading all fault codes present, and about 30-45 minutes of the technicians time analyzing and interpreting the data. If more time is needed, additional charges will apply based on reasonable time to run the additional diagnostic tests.
Diagnosing vehicles requires:
- Special equipment that costs anywhere from $1000-$10,000 per machine
- Subscriptions to different programs like ALLDATA and MITCHELL as well as various OEM Manufacturers data sites which provide TSB's, recall information, flow charts and electrical diagrams $varies greatly
- Different classes the technicians attend to stay up to date with the latest in diagnostic procedures which all cost $50-350 per technician per class
- Materials used while diagnosing such as jumper wires, paper to print out different test procedures, batteries for various testers etc.
All this coupled with the Technicians pay for the time spent, normal overhead costs such as Electric, Water and Sewer, make up the diagnostic charges you see on your bills.