Pinpoint Test : Brake Vacuum Assist Function

PINPOINT TEST A: BRAKE VACUUM ASSIST FUNCTION
TEST CONDITIONS	DETAILS/RESULTS/ACTIONS
A1: CHECK THE BRAKE PEDAL TRAVEL WITH THE ENGINE OFF
1. Set ignition switch to OFF.
2. Pump the brake pedal six times and hold firm pressure on the pedal.
Did the pedal travel decrease and the pedal go hard as it was pumped? Yes GO to A2. No CHECK the vacuum circuit to the brake booster. Start the engine and idle for three minutes, switch ignition OFF then repeat the test. If the pedal travel does not decrease, suspect the brake booster.

A2: CHECK THE BRAKE PEDAL TRAVEL WITH THE ENGINE RUNNING
1. With firm pressure still held on the brake pedal, start the engine.
Did the pedal travel increase as the engine started? Yes The vacuum function of the brake booster is operating normally. Check for DTCs indicating a fault elsewhere in the system. No CHECK the vacuum circuit to the brake booster.