The vehicle has a number of computers that record information about the vehicle's performance and how it is driven. For example, the vehicle uses computer modules to monitor and control engine and transmission performance, to monitor the conditions for airbag deployment and deploy them in a crash, and, if equipped, to provide antilock braking to help the driver control the vehicle. These modules may store data to help the dealer technician service the vehicle.
Some modules may also store data about how the vehicle is operated, such as rate of fuel consumption or average speed. These modules may retain personal preferences, such as radio presets, seat positions, and temperature settings.
Reporting Safety Defects to
General Motors
Event Data RecordersMeasuring Frequency
Special Tools EL–39200 Digital Multimeter (DMM)For equivalent regional tools, refer toSpecial Tools.Caution:Refer toTest Probe Caution.The following procedure determines the frequency of a signal.Note:Connecting the Digital Multimeter (DMM) to the circuit before pressing the Hz buttonwill allow th ...