C002100 - C002100 Brake Booster Module Line Hydraulic Pressure Below Normal Value-OBD

Fault Depth Definition

DTC C002100 (Brake Booster Module Line Hydraulic Pressure Below Normal Value-OBD) is a critical fault code in the vehicle diagnostic system, identifying pressure monitoring anomalies within the Intelligent Power Brake System (IBS / EHB). This fault code indicates that the working hydraulic pressure actually established inside or in the lines connected to the Brake Booster Module has not reached below the safety threshold set by the Intelligent Power Brake Controller. Under the ECU architecture, this parameter belongs to the core variable of the active safety feedback loop, directly related to the driver's perception of the brake pedal and basic support for vehicle dynamic stability. The system's recording of this fault code indicates that the deviation between the physical fluid pressure signal and the logical expected value has exceeded the allowable tolerance range, triggering OBD system safety strategy intervention.

Common Fault Symptoms

When the Intelligent Power Brake Controller detects the above deviation and meets specific trigger conditions, the vehicle will feedback the following status to the driver or onboard information terminal:

• Instrument Panel Indication Feedback: The brake booster warning light (Exclamation Mark in Circle/Brake Warning Lamp) on the dashboard lights up, indicating system functionality degradation.
• Degraded Power Assist Performance: Partial failure of Intelligent Power Brake System functions, manifested as heavier pedal resistance or delayed brake assist feedback, resulting in vehicle response lag.
• System Diagnostic Logic Lock: When an OBD diagnostic tool reads this code, it can confirm long-term deviation or instantaneous drop in hydraulic sensor data flow versus target value.

Core Fault Cause Analysis

Based on the physical correlation and signal integrity principles of OBD diagnostic data, fault triggers can be technically qualified from three dimensions: hardware components, fluid paths, and electronic controllers:

• Hardware Component Integrity Failure: Brake line leakage. Aging mechanical seals, ruptured lines, or loose fittings cause hydraulic medium loss, directly causing system pressure to fail maintaining within the set interval.
• Abnormal Fluid Transmission Physical Characteristics: Air mixed into Intelligent Power Brake Controller Brake Booster Module lines. The compressibility of an air-liquid mixture is much greater than liquid; under high-pressure conditions, this leads to torque transmission attenuation, manifested as pressure readings below normal value, accompanied by a "pedal void" sensation.
• Electronic Sensor and Logic Calculation Error: Internal Pressure Sensor Fault in Intelligent Power Brake Controller. Damage to the sensor's diaphragm, drift, or distorted output signal leads the control unit to receive erroneous feedback voltage/signal values, resulting in determination of insufficient pressure.

Technical Monitoring and Trigger Logic

The Intelligent Power Brake Controller follows strict threshold comparison logic for real-time evaluation of hydraulic state:

• Monitoring Target: System continuously collects real-time hydraulic actual pressure value at the Intelligent Power Brake Controller port, and compares/analyzes with preset Target Pressure.
• Judgment Basis: The essential judgment standard for fault occurrence is: Deviation between Hydraulic Actual Pressure Value and Target Pressure exceeds set range. Control unit calculates deviation value via algorithm $ \Delta P = |P_{actual} - P_{target}| $, where deviation continues to exceed threshold satisfies fault definition.
• Trigger Condition: Fault record activation condition is Ignition Switch Placed in ON Position. System begins pressure reference calibration and real-time monitoring after ignition switch opens, power enters Ready state or system self-check completes; if pressure drops abnormally during this period, immediately record DTC C002100.