Subject: | Service Brakes Soon Message DTC C0299 |
Models: | 2007-2008 Cadillac Escalade, Escalade ESV, Escalade EXT |
2007-2008 Chevrolet Avalanche, Silverado, Suburban, Tahoe |
2007-2008 GMC Sierra, Yukon, Yukon XL, Yukon Denali, Yukon Denali XL |
This PI was superseded to update Recommendation/Instructions. Please discard PIT4046D.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Some customers may experience a "Service Brakes Soon" message on the Drivers Information Center (DIC). After initial inspection, you may find a current or history code C0299. Diagnostic code C0299 can result from two issues. The first may be an electrical concern with the Active Brake Booster solenoid or related wiring. The second may be low vacuum detected in the brake booster.
If the DTC C0299 sets immediately after cycling the key, an electrical concern with the Active Brake Booster solenoid or the related wiring may be the cause. Diagnose the concern using normal diagnostics in SI.
If the DTC C0299 sets occasionally while driving or when using the cruise control feature, the concern may be related to a vacuum leak. Diagnose the concern using normal diagnostics in SI. DTC C0299 diagnostics should lead to the Brake Assist System Diagnosis process to investigate for a possible vacuum leak. Follow the Brake Assist System Diagnosis process to determine if a vacuum leak is present and what the appropriate repair is to fully restore the Brake Assist System. Some reports from the field have shown one source of a vacuum leak is the o-ring seal between the brake master cylinder and brake booster, refer to bulletin 08-06-04-016 for more information.
DTC C0299 00 may be an electrical concern with the Active Brake Booster solenoid or the related wiring. Diagnose the concern using normal diagnostics in SI.
DTC C0299 5A may be related to a vacuum leak. Diagnose the concern using normal diagnostics in SI. DTC C0299 diagnostics should lead to the Brake Assist System Diagnosis process. 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 process to determine if a vacuum leak is present and what the appropriate repair is to fully restore the Brake Assist System. Some reports from the field have shown one source of a vacuum leak is the o-ring seal between the brake master cylinder and brake booster, refer to bulletin 08-06-04-016 for more information.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.