Request AUTOSTART In AUTOSTOP, Brake Vacuum

Causes of system requested autostart in autostop:

• Incorrect pressure (vacuum too low) in the brake booster

Checks:

• Check the brake booster's function and non-return valve for air leaks. With the engine just shut off the vacuum in the brake booster should be enough for a few vacuum assisted brake attempts.
• Check for air leaks in the vacuum hoses between the brake booster and motor.
• Check that the vacuum pressure sensor works properly.

HINT: Read off the air pressure in the brake booster via Diagnostics/Components/Diagnostic Sequences/Vehicle Dynamics Domain Master (VDDM), BCM in VDDM/Parameters.