Today's cars and trucks have many lights that can come on the dash to warn the driver of a problem in a particular system. Many times when multiple lights are on, these can be related to the same problem.
Computers "TALK" to each other. So, a problem in one system can affect one or more other systems. Sometimes this will cause a system to be disabled and the warning light to come on, even though that system does not have a problem.
A good example of this is that a problem in the ABS will usually cause the Traction Control to be disabled. You may have an indicator that shows "TRAC Off". That does not neccesarily mean there is a fault in the Traction control function.
The vehicle stability enhancement system (VSES) provides added stability during aggressive maneuvers. Yaw rate is the rate of rotation about the vehicle's vertical axis. The system is activated when the electronic brake control module (EBCM) determines that the desired yaw rate does not match the actual yaw rate as measured by the yaw rate sensor.
The supplemental inflatable restraint (SIR) system supplements the protection offered by the occupant seat belt system. The SIR system has several inflater modules located throughout the vehicle, i.e. The inflatable restraint steering wheel module, inflatable restraint IP module in passenger side of dash,
The anti-lock braking system (ABS) uses several sensors, motors, and a computer in conjunction with the normal braking system.
The ABS regulates the brake pressure in order to reduce wheel lock-ups. Reduced wheel lock-ups improve the driver's control of the vehicle during braking.
Theft / Security Light
The security system on today's cars and trucks prevents the vehicle from being stolen. There are many variations of the system going back to the early 1990's.
The tire pressure monitor system in today's cars use a radio frequency (RF) transmitter ( Tire Pressure Sensor ) in each wheel valve stem to relay pressure information to the module. The Service Tire Pressure Monitor System light / warning means there is a problem in the system, not a low tire.
Today's cars and trucks use many sensor, switches, solenoids, and other electrical components to control or monitor every aspect of the engine.From controlling the fuel and ignition systems, to monitoring the emissions. A problem in any of these systems, or subsystems, can cause the check engine light to come on.
The dash, also know as the instrument cluster, or IPC, illuminates the SERVICE VEHICLE SOON indicator light when the following things occur:
The body control module (BCM) detects certain malfunctions in the lighting system.
The IPC receives a class 2 message from the BCM requesting illumination.
