Caddy says Whoa
Some owners of a 2009 and later Cadillac Escalade may experience a “Service Brakes Soon” message on the DIC.
After initial inspection, you may find a current or history code C0299. While previous model year vehicles can show this code due to one of two issues….an electrical concern with the Active Brake Booster solenoid or related wiring; or low vacuum detected in the brake booster, the 2009-later models no longer feature an Active Brake Booster solenoid, so DTC C0299 will only set one symptom 5A, which may be related to a vacuum leak.
Diagnose the concern using normal diagnostics. New Tech 2 vacuum sensor data information is available for this concern (Tech 2 software version 28.001 or greater).
Follow the Brake Assist System diagnosis procedure to determine if a vacuum leak is present.
Some reports from the field have shown that one source of a vacuum leak is the O-ring seal between the brake master cylinder and brake booster.