C0299

DTC C0299

Diagnostic Instructions

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

DTC Descriptor

DTC C0299 5A

Brake Booster Large Vacuum Leak Detected Not Plausible

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 seconds.

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

Connector End View Reference

Component Connector End Views

Description and Operation

Brake Assist System Description and Operation

Electrical Information Reference

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

Scan Tool Reference

Control Module References

Circuit/System Testing

1. Ignition ON, verify that DTC C1100 is not present.
2. If DTC C1100 is present, refer to DTC C1100. C1100
3. Inspect the brake booster vacuum system for damage, leakage and correct installation. Refer to Brake Assist System Diagnosis. Brake Assist System: Diagnostics
4. If the brake booster vacuum systems diagnoses normal, replace the B19B Brake Booster Vacuum Sensor and verify the DTC does not reset. If the DTC resets, replace the K17 Electronic Brake Control Module (EBCM).

Repair Instructions

Perform the Diagnostic Repair Verification

- Power Brake Booster Vacuum Sensor Replacement
- Control Module References