The Check Engine/Service Engine Soon light comes on when there is an emissions, ignition, fuel system or transmission related failure. This light does not mean that you just need routine maintenance. There are many different failures that may cause this light to come on. If the light is on solid, you’ll want to bring your vehicle in as soon as possible. If the light is flashing, this is more serious. If the vehicle continues to be driven in this condition it could lead to very costly emission repairs.
When diagnosing a check engine light issue the technician must first road test your vehicle in order to detect any drivability issues. Then they need to connect a scanner to evaluate data stream and codes that are stored in the vehicle on board computer. The stored codes or data that is out of range will direct the technician to a specific problem area. In many cases there are multiple codes and problem areas that may require additional labor time to further investigate and diagnose. The technician must now access several subscription -based on line automotive repair databases to obtain the proper diagnostic and repair procedures. Once the technician determines what is causing the problem they can now estimate the cost of the repair. The diagnostic time spent troubleshooting is generally not included with the cost of the repair. We strongly recommend that when your check engine light comes on that you take your vehicle into a California Certified Smog Check Test and Repair facility where specially trained ASE qualified technicians can accurately diagnose and repair your vehicle.
Six of the most common malfunctions that cause the check engine light to come on are:
- Loose or Faulty Gas Cap
- Vacuum Leaks
- Spark Plugs, Ignition Coils or Ignition Wires
- Oxygen Sensor
- Mass Air Flow Sensor
- Catalytic Converter
There are many other possibilities for a check engine light to come on, but the above six are the most common.