Circuit Description

This DTC is used to identify the conditions of brake switch circuit. The EBCM sends a low current 5 volt sense voltage on brake switch input line to the rear brake light bulbs. If the rear brake light circuit is intact, this voltage will be pulled low (under 1 volt) to ground through the rear brake light bulbs. When the brake light switch is depressed, battery voltage will be supplied to the rear brake lights and to the EBCM, indicating brake lights are on. C0093 can be set if test C0091 failed the previous ignition cycle. Once C0093 is set, it will be reset each ignition cycle until a brake switch input is seen.