The brake light switch illuminates the rear brake lights when the brake pedal is applied and is referred to as the brake on-off (or BOO) switch, functioning as a digital information switch for the powertrain control module. Located at the upper end of the brake pedal, at the connection between the pedal pin and the power brake booster pushrod, access to the switch and connector requires removing the trim panel beneath the steering column. If the brake lights are inoperative, the first step is to check the fuse. If the fuse is good, check for voltage to the switch on the feed wire; if no voltage is present, repair the wire between the switch and the fuse box. If voltage is present, depress the brake pedal and check for voltage at the output wire terminal; if no voltage is present, replace the switch. If voltage is present, check for power on the brake light wires at the tail light housings with the brake pedal depressed; if voltage is not present, repair the circuit between the switch and the brake lights. If voltage is present, check for a bad ground by using a jumper wire connected to a good ground to probe the ground wire terminal at the tail light connector; if the brake lights go on, repair the ground circuit. It is also important to consider that the brake light bulbs could be burned out, although the likelihood of all bulbs being burned out is very slim. To remove the switch, first remove the trim panel below the steering column, unplug the electrical connector from the switch, remove the retaining pin, and disengage the brake light switch from the master cylinder pushrod and the pin on the brake pedal, noting the installation of the nylon washers to ensure they are installed the same way during reassembly, which follows the reverse order of removal.