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 Descriptor

DTC C0299: Brake Booster Performance

### Circuit/System Description

The electronic brake control module (EBCM) monitors the vacuum level in the power brake booster, and will set a DTC if the vacuum is too low.

### Conditions for Running the DTC

• | The ignition is ON.

• | Ignition voltage is greater than 9 volts.

• | The engine is running for the vacuum related fault to set.

### Conditions for Setting the DTC

• | A condition in which no vacuum is detected in the power brake booster for approximately 10 seconds after start-up.

• | A condition in which low vacuum is detected in the power brake booster for approximately 60 seconds or longer after start-up, or is detected while driving.

### Conditions for Clearing the DTC

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

• | The EBCM automatically 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 Reference

ABS Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

• | Connector Repairs

#### Scan Tool Reference

Control Module References

### 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 Diagnostic Trouble Code (DTC) List - Vehicle .