Check Engine & Other Warning Lights

Vehicles today are equipped On-Board Diagnostics which consist of intricate computer modules that monitor the performance of various systems and components.  If a fault is detected a warning light illuminates on the dash alerting the driver to a problem and in some cases a diagnostic trouble code (DTC) is stored.  If a warning light comes on, refer to your owner’s manual for a description.  If you don’t have your owner’s manual, the internet is also a good source to find descriptions of dash warning lights.  Following are some common warning lights.

Check Engine Light

First required in California in 1991, the on-board diagnostics system monitors the various systems that affect the cars emission performance.  An illuminated Check Engine Light indicates that one or more of the systems and/or components associated with your vehicle’s emissions output isn’t working properly.  When this occurs a DTC is stored to help identify the problem.  One very common problem is a loose or improperly sealed gas cap. While this light is on you will not be able to pass a smog inspection and you may or may not notice a change in engine performance.  Whether or not you are experiencing performance problems with an illuminated check engine light, it’s best to take the car to your mechanic as soon as possible.  Although the light indicates emission related problems, improperly functioning emission components could potentially damage other components.

Foothill Auto Service offers free diagnostic code scan for 1996 and new vehicles.

Brake Light

The Brake warning light typically indicates that the hydraulic fluid used for braking is low.  Low brake fluid can result from a leak in the system or can indicate that your brake pads are low.  This light can also indicate a problem with your Anti-lock Brake System.

ABS Light – Anti-lock Brake System

The ABS light indicates that there is a malfunction within the Anti-lock Brake System.  Typically, when this light is illuminated the vehicle’s on-board diagnostic system has stored a code, which can be retrieved and assist in diagnosing the problem.  When this light is on, the Anti-lock portion of your braking system will not function.

Coolant Temp

This light indicates that the vehicle’s engine temperature has exceeded normal operating limits.  This light could be the result of any number of cooling system related problems; low coolant level, a faulty cooling fan, plugged radiator, etc.  If this light comes on, it is best to stop operating the vehicle as soon as possible to avoid engine component damage.

SRS Light – Supplemental Restraint System (airbags)

This light indicates that there is a problem with the Airbag system of the vehicle.  Typically, when this light is on, the vehicle’s on-board diagnostic system has stored a code which can be retrieved for help in diagnosing the problem.  Airbag components can be very dangerous.  Diagnostics and repair are best left to professionals.  While this light is on, your airbag system will not operate.

TPMS Light – Tire Pressure Monitor System

This light indicates that one or more of the vehicle’s tires is not properly inflated or there is a faulty sensor.  Check and adjust your tire pressure.  If the light continues to illuminate with the correct air pressure in all tires, chances are there could be a problem with a sensor.