For 1990-2009 cars

### 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 Descriptors

DTC C0299 00: Brake Booster Pressure Sensor Performance
DTC C0299 5A: Brake Booster Pressure Sensor Performance Plausibility Failure

### Circuit/System Description

The power brake booster vacuum sensor monitors the vacuum level in the power brake booster. When the electronic brake control module (EBCM) detects the vacuum level is low a DTC is set.

### Conditions for Running the DTC

The engine is running.

### Conditions for Setting the DTC

Low or no vacuum is detected in the power brake booster after start-up.

### Conditions for Clearing the DTC

• | The condition for the DTC is no longer present.

• | The EBCM clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

### Reference Information

#### Schematic Reference

Antilock Brake System Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

ABS 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 for scan tool information

### Circuit/System Verification

1. Verify that a vacuum leak is not present, refer to Brake Assist System Diagnosis.
2. Verify that DTC C1100 is not set.

⇒ | If DTC is set, refer to DTC C1100.