AU
C002192

This fault code indicates the IPB (Integrated Power Brake) system detects pressure inside the brake booster chamber below the normal operating threshold — Seal U

Braking System

This fault code indicates the IPB (Integrated Power Brake) system detects pressure inside the brake booster chamber below the normal operating threshold.

In models such as the Song PLUS DM-i, the IPB system generates brake assist pressure via an electric vacuum pump or direct motor drive and continuously monitors this pressure using a pressure sensor.

The system triggers DTC C002192 when it detects assist pressure remaining below the target value (typically below -0.6bar or the set threshold range) for longer than the specified time (e.g., 500ms) and rules out sensor signal interference.

This fault causes a hard brake pedal and increased braking distance.

The system restricts the regenerative braking function and illuminates the ABS/ESC warning light.

Extreme conditions may trigger Limp Home mode, severely compromising driving safety.

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Cases Logged
5
Causes
Likely Causes — Seal U
  • 1Electric vacuum pump assembly fault: Worn vacuum pump motor carbon brushes, aging pump body vanes, or a drive circuit fault prevents the pump from building sufficient vacuum (common in vehicles over 60,000 km).
  • 2IPB integrated module internal pressure sensor fault: Sensor signal drift, internal circuit fault, or sensor-to-hydraulic chamber seal failure causing a false low-pressure warning.
  • 3Vacuum line system leak: Aging or cracked vacuum lines, vacuum reservoir seal failure, loose line joints, or a sticking check valve, causing insufficient vacuum retention.
  • 4IPB module internal hydraulic circuit fault: Stuck booster valve (Solenoid Valve), damaged internal sealing ring, or hydraulic fluid leak preventing booster pressure buildup.
  • 5Abnormal power supply: Burnt IPB module main relay contacts, excessive fuse contact resistance, or loose ground wiring causes insufficient supply voltage to the assist motor/vacuum pump.
What To Do
  • 1
    Use the VDS2000/VDS3000 diagnostic tool to read the DTC freeze frame data. Record the vehicle speed, brake pedal travel, Brake Booster Pressure, and vacuum pump status when the fault occurred to determine whether the fault is intermittent or persistent.
  • 2
    Visually inspect the IPB module exterior for signs of brake fluid leakage. Check the wiring harness connectors (especially the 24-pin main connector) for oxidation or looseness. Check the vacuum lines (if applicable) for cracks, collapse, or loose connections.
  • 3
    Enter the IPB system data stream and read the 'Brake Booster Pressure' real-time value. With the ignition switch ON (do not press the pedal), the normal value is -0.8 to -1.0 bar (vacuum). A reading near 0 bar or atmospheric pressure indicates the vacuum system failed to build vacuum or the sensor is faulty.
  • 4
    Perform the vacuum pump actuation test: Activate the electric vacuum pump using the diagnostic tool. Listen for normal pump operation (no abnormal noise, stable speed) and observe the pressure drop rate. Normally, pressure drops from 0 to below -0.7 bar within 3 seconds. If the pressure drops slowly or the vacuum pump does not operate, check the vacuum pump power supply (12V) and ground circuit.
  • 5
    Perform a vacuum holding test: Operate the vacuum pump until the system reaches maximum vacuum, then stop the pump. Observe the pressure drop over 1 minute. If the pressure drop exceeds 0.1 bar/min, a vacuum leak exists. Check the sealing of the vacuum tank, check valve, vacuum booster body, and lines section by section.
  • 6
    Check IPB module power supply and communication: measure voltage at IPB module power terminals (+30, +15) (should be ≥12.4 V), check CAN-H and CAN-L line voltages (approx. 2.5 V) and terminating resistance (approx. 60 Ω), and rule out false sensor alarms caused by low voltage.
  • 7
    If the vacuum system is normal but the pressure sensor data is abnormal, or the IPB internal hydraulic unit leaks, replace the IPB integrated electro-hydraulic brake module assembly (part number usually starts with 6A). After replacement, use the diagnostic tool to perform the 'IPB Bleeding Procedure' and 'Pressure Sensor Zero Point Calibration'.
  • 8
    Clear the fault code and perform a road test to verify: on a flat, straight road, perform multiple medium-to-high-speed braking applications (40km/h→0). Confirm brake pedal effort is normal, the ABS/ESC warning light is off, and the fault code does not return.
Real-World Cases
BYD DTC AI Analysis

Song PLUS DM-i: Worn vacuum pump carbon brushes cause intermittent DTCs

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Vehicle: 2021 Song PLUS DM-i, 82,000 km. Symptoms: ABS warning light intermittently illuminates during cold starts (DTC C002192), clears after warm-up; brake pedal gradually stiffens. Diagnosis: Live data revealed the vacuum pump running continuously but only reaching -0.45 bar, below threshold. Disassembly revealed motor brushes worn to their limit (<5 mm) and a burnt commutator. Solution: Replaced the electric vacuum pump assembly (with control module) and performed IPB system calibration. Fault resolved. Service tip: DM-i vacuum pumps operate more frequently than conventional fuel vehicles; inspect the pump every 60,000 km.
BYD DTC AI Analysis

IPB module pressure sensor drift false alarm

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Vehicle: 2021 Song PLUS DM-i, 35,000 km. Issue: Brake system warning light illuminates intermittently while driving; DTC C002192 stored, but brake pedal feels normal without hardening. Diagnosis: Scan tool showed booster pressure at -0.05 bar (near atmospheric), contradicting actual brake feel. Checked vacuum lines—no leaks. Vacuum pump works normally. Found signal drift in the IPB internal pressure sensor. Fix: Replaced the IPB integrated electro-hydraulic brake module assembly (new module requires VIN matching). Performed brake line bleeding and sensor zero-point learning after replacement. Fault eliminated.
BYD DTC AI Analysis

Stuck vacuum line check valve causing pressure leak

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Vehicle: 2021 Song PLUS DM-i, 48,000 km. Symptoms: DTC C002192 sets after extended downhill driving or frequent braking, clears after restart. Diagnosis: Static pressure hold test showed vacuum dropping from -0.8 bar to -0.4 bar within 30 seconds—severe retention loss. Step-by-step inspection found the vacuum pump outlet check valve stuck half-open, causing vacuum backflow. Repair: Replaced the vacuum check valve (integrated in the vacuum line), cleaned the vacuum pump port, applied a thin layer of vacuum silicone grease on reassembly, and confirmed normal pressure retention. Fault resolved.
BYD DTC AI Analysis

Outdated IPB module software caused false fault codes.

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Vehicle: 2021 Song Plus DM-i, 21,000 km. Fault: C002192 sets intermittently during high-speed driving (>100 km/h), with the ESC OFF light flashing. Diagnosis: Checked vacuum system and power supply circuits; both normal. Fault frequency extremely low (once per month). Consulted BYD Technical Service Bulletin (TSB) and identified an IPB control software defect for this VIN range. The software falsely triggers pressure monitoring logic under specific combinations of vehicle speed and brake pedal rate. Resolution: Updated IPB module software to latest version (≥V2.3.5). No recurrence after one month of monitoring post-update.
Other Seal U Fault Codes
B1108For the BYD Song MAX (2017–2019), DTC B1108 indicates a short circuit in the PM2.5 air quality detection module (dust sensor) or its wiring harness. The sensor uses laser scattering to detect in-cabin and outside PM2.5 concentrations and transmits data to the HVAC ECU via the LIN bus or an analog signal. Short circuit conditions include: 1) Sensor power supply wire (+5V/+12V) shorted to ground 2) Signal wire shorted to power or ground 3) Short circuit in the sensor's internal photoelectric detection circuit This fault prevents the automatic climate control from switching between fresh air and recirculation based on air quality. The system enters fail-safe mode (typically forced recirculation). Severe short-circuit current can destroy the HVAC ECU sampling circuit. The system classifies this as a Level 3 severe fault and restricts vehicle operation to prevent electrical fires or controller damage. For other BYD models (such as the Qin EV, E5, and Song DM), B1108 indicates a driver-side sunload sensor fault, reflecting differences in DTC definitions across models.B110811This DTC indicates a short circuit in the air conditioning system PM2.5 air quality sensor (rapid detector). Specifically, abnormal continuity exists between the sensor power supply circuit or signal output circuit and body ground or battery positive. This causes the control module (ACU/air conditioning controller) to detect abnormal current or a voltage signal outside the valid range (typically 0V or supply voltage). The PM2.5 sensor monitors internal and external particulate concentrations, providing the data the automatic air conditioning system uses to switch between fresh air and recirculation modes. A short circuit disables the air quality monitoring function. This fault may force the air conditioning system into recirculation protection mode and trigger related thermal management system faults, as the air conditioning system acts as a key actuator in vehicle thermal management. In severe cases, the short circuit current can damage the internal sampling circuit of the air conditioning controller or overheat the wiring harness.B1109DTC B1109 indicates an open circuit in the communication line between the air conditioning system PM2.5 air quality sensor (dust concentration sensor) and the air conditioning control unit (AC ECU), or an open circuit within the sensor internal circuitry. Typically located in the air conditioning intake duct, this sensor monitors real-time PM2.5 particle concentration inside and outside the vehicle. It provides data to the automatic air conditioning system for intelligent switching between fresh air and recirculation modes and for controlling the air purification device. During an open circuit fault, the AC ECU cannot receive the air quality signal, triggering the system fail-safe mode. Symptoms typically include failure of the automatic recirculation function, abnormal air purification indicator light operation, or abnormal air quality data displayed on the air conditioning panel. Severe cases may compromise the cabin environment control strategy, but do not directly affect vehicle driving safety.B110913DTC B110913 indicates an open signal circuit for the PM2.5 rapid detector (in-cabin air quality sensor). This sensor typically mounts inside the air conditioning system intake duct. It monitors in-cabin PM2.5 concentration in real time and provides data to the automatic air conditioning system for intelligent control of the air purification function. The BYD diagnostic protocol uses sub-code '13' to specifically indicate an open signal circuit. Although this fault theoretically affects a comfort feature, BYD Qin series vehicles classify it as a Level 3 (severe) fault. This classification occurs because the air conditioning system interacts with the battery thermal management system (e.g., monitoring battery cooling intake air quality). The fault can disable the automatic air conditioning mode and prevent the air purification function from operating. In extreme cases, it affects the battery compartment intake air quality assessment, triggering the 'repair immediately' strategy.B110AThis DTC indicates interrupted CAN bus communication or abnormal data between the air conditioning control unit (ACU) and the PM2.5 air quality sensor. The PM2.5 sensor monitors particulate concentration inside and outside the vehicle and provides the basis for purification control in the automatic air conditioning system. The ACU triggers this fault if it fails to receive a valid CAN message from the sensor within the specified period (usually 100-500 ms), if message verification fails, or if the signal frame times out. Although this fault does not affect vehicle driving safety, it disables the automatic air purification function. The air conditioning system cannot automatically switch between recirculation and fresh air modes or activate the air purification mode based on air quality. A persistent fault may restrict the thermal management strategy.
Data confidence: Official This information is for reference only. Always consult a qualified technician for diagnosis and repair. Do not attempt high-voltage system repairs yourself.