GM Service Manual Online
For 1990-2009 cars only

Your GM vehicle has a number of sophisticated computers that record information about the vehicle’s performance and how it is driven. For example, your vehicle uses computer modules to monitor and control engine and transmission performance, to monitor the conditions for airbag deployment and deploy airbags in a crash and, if so equipped, to provide antilock braking to help the driver control the vehicle. These modules may store data to help your dealer/retailer technician service your vehicle. Some modules may also store data about how you operate the vehicle, such as rate of fuel consumption or average speed. These modules may also retain the owner’s personal preferences, such as radio pre-sets, seat positions, and temperature settings.