C0299

DTC C0299

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor
DTC C0299 56
- Brake Booster Large Vacuum Leak Detected Too Many Transitions

Diagnostic Fault Information






Circuit/System Description

The brake booster vacuum sensor measures the vacuum in the brake booster assembly. The electronic brake control module (EBCM) supplies a 5 V reference and a low reference circuit to the brake booster vacuum sensor. The vacuum sensor supplies a voltage signal in relation to the pressure in the brake booster to the EBCM.

Conditions for Running the DTC

Ignition ON

Conditions for Setting the DTC

The EBCM detected a too low vacuum in the brake booster assembly for 120 s.

Action Taken When the DTC Sets

The brake warning indicator turns ON.

Conditions for Clearing the DTC

* A current DTC clears when the diagnostic runs and passes.
* The EBCM will turn OFF the indicator in the next ignition cycle.

Reference Information
Schematic Reference

Hydraulic Brake Schematics [1][2]Electrical Diagrams
Connector End View Reference

Component Connector End Views Connector End Views By Name
Description and Operation

Brake Assist System Description and Operation Brake Assist System
Electrical Information Reference

* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Testing

1. Ignition ON, verify that DTC C1100 is not set.

• If DTC C1100 is set, refer to DTC C1100 C1100.

2. Inspect the brake booster vacuum system for damage, leakage and correct installation. Refer to Brake Assist System Diagnosis Component Tests and General Diagnostics.
3. If the brake booster vacuum systems diagnoses normal, replace the B19B Brake Booster Vacuum Sensor and verify the DTC does not set. If the DTC set, replace the K17 Electronic Brake Control Module.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Power Brake Booster Vacuum Sensor Replacement Service and Repair
* Control Module References Control Module References