Computers and Control Systems: Service Precautions

Aftermarket (add-on) electrical and vacuum equipment is any device installed on to a vehicle after the vehicle has left the factory that connects to the electrical circuits or vacuum hoses of the vehicle.

NOTE:
^ Do not attach add-on vacuum operated equipment to this vehicle. The use of add-on vacuum equipment may result in damage to vehicle components or systems.
^ Connect any add-on electrically operated equipment to the vehicle's electrical system at the battery (power and ground) in order to prevent damage to the vehicle.

Add-on electrical equipment installed as instructed can cause the system to malfunction.

Add-on electrical equipment not connected to the vehicle electrical circuits can cause the system to malfunction. Examples of these types of equipment include the following:
^ Portable telephones
^ Portable radios

Disconnect all add-on equipment in order to diagnose a malfunction.