The models covered are equipped with Supplemental Restraint systems (SRS), commonly known as airbags. Always disconnect the negative battery cable followed by the positive battery cable and wait two minutes before working near the impact sensors, steering column, or instrument panel to avoid accidental airbag deployment, which could cause personal injury. To check the switch, it must first be removed. Using an ohmmeter or self-powered test light along with the accompanying diagrams, check for continuity between the indicated switch terminals in each of the specified positions. If continuity is not as specified, replace the switch. For 2002 and earlier models, disconnect the negative battery cable, turn the headlight switch to the ON position, and pull the knob outward to the fog light ON position. Use a small screwdriver to pry the knob off the headlight switch, ensuring the knob is positioned so that the headlights and fog lights are ON. Turn the knob 180 degrees from the ON position and reinstall it back onto the headlight switch. Turn the headlight switch to the OFF position, then rotate the knob clockwise as far as possible while holding it to enable the locking tab on the back of the switch to retract, allowing the headlight switch to be removed from the instrument panel. Unplug the electrical connector from the back of the switch and remove it from the vehicle, with installation being the reverse of removal. For 2003 and later models, remove the driver's knee bolster. On models with a removable switch panel, pry the panel out, disconnect the electrical connectors, and remove the screws securing the switch to the back of the panel. On models where the switch is mounted to the instrument panel, disconnect the electrical connector from behind and release the tabs securing the switch to the instrument panel.