Brake Signal: Description and Operation

PURPOSE
The stoplight switch signal comes from the stoplight circuit and signals the powertrain control module engine (PCME) when the brakes are applied.

OPERATION
The PCME monitors the stoplight circuit through PCME terminal 2L. When the brake pedal is released, the voltage in the stoplight circuit is zero. When the brake is applied, voltage in the circuit goes to approximate battery voltage. The PCME interprets the voltage signal as a "brake applied and/or deceleration condition".