Normal Operation

The active brake booster contains a normally open and a normally closed pedal force switch that operates according to driver brake applications. When the driver applies enough force to the brake pedal, the normally open switch will close and the normally-closed switch will open.

The ABS module provides a reference voltage to the pedal force switch along circuit CCA29 (GN/BU). The voltage returns along either the normally open pedal force circuit CCA26 (BU/GY) or the normally closed pedal force circuit CCA25 (VT/GY), depending on the driver brake application.

• DTC C1287 Brake Booster Pedal Force Switch Circuit Failure - If, during normal operation or the ABS module on-demand self test, the ABS module detects an open circuit, a short to voltage or a short to ground on circuits CCA26 (BU/GY) or CCA25 (VT/GY), DTC C1287 will be set. Also, a failure of the booster pedal force switch will cause DTC C1287 to be set.

This pinpoint test is intended to diagnose the following:

• Wiring, terminals or connectors
• Active brake booster
• ABS module