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U030000

In the BYD IPB (Intelligent Power Brake) integrated braking system, U030000 indicates the brake control unit (IPB ECU) internal software is incompatible with the vehicle network configuration — Qin Plus

Braking System

In the BYD IPB (Intelligent Power Brake) integrated braking system, U030000 indicates the brake control unit (IPB ECU) internal software is incompatible with the vehicle network configuration.

Specifically, the IPB module software version number, Calibration Verification Number (CVN), or configuration word (Coding) does not match the vehicle VCU, Gateway, and other CAN nodes.

This prevents the brake control strategy from loading normally or causes verification failure.

The fault triggers the system safety protection mechanism, restricting regenerative braking, Automatic Emergency Braking (AEB), and ESC functions.

Severe cases cause a hard brake pedal, limit brake assist, or force the vehicle into limp mode.

This functional fault compromises driving safety.

The U030000 fault code on the Qin Plus indicates a medium-severity software compatibility problem in the IPB brake control unit. Its software version, coding, or calibration data may not match the vehicle network, which can limit braking assist, regenerative braking, ESC, or AEB. Common causes include incorrect IPB software or missing online matching after replacing the unit. Visit an authorised dealer for diagnosis, coding, and software correction. Typical repair cost data is available.
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Cases Logged
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Causes
Likely Causes — Qin Plus
  • 1Incorrect IPB ECU software version (incorrectly flashed software package for another vehicle model, model year, or trim level)
  • 2Failure to perform online matching, coding, and anti-theft synchronization after replacing the IPB assembly with a salvaged or used part.
  • 3Interruption during software flashing (battery voltage below 12V, unstable OBD connection, or diagnostic tool crash) resulting in program block corruption.
  • 4Vehicle network configuration data (CVN/AS-BUILT data) missing or inconsistent with the gateway module configuration.
  • 5Corrupted IPB internal EEPROM data (caused by prolonged 12 V battery discharge, strong electromagnetic interference, or hardware aging)
What To Do
  • 1
    Use VDS2000 or a dedicated BYD diagnostic tool to read the fault code. Confirm U030000 is a current fault, not a history fault. Record the current IPB software version (e.g., BGM+ version) and hardware part number.
  • 2
    Check the IPB ECU power supply (constant power 30+B, ignition switch IG power), ground points (G101/G102), and CAN-H/CAN-L voltages (recessive 2.5 V, dominant 3.5 V/1.5 V) to rule out software checksum errors caused by power supply fluctuations.
  • 3
    Check the vehicle VIN and IPB label part number to confirm the hardware matches the vehicle configuration (e.g., Song PLUS DM-i requires a specific IPB model; do not mix ICE and hybrid IPB units).
  • 4
    Perform 'online programming' or 'software flashing': Connect the diagnostic tool to the BYD cloud server and download the latest IPB software package for the corresponding VIN (usually .hex or .s19 format). During flashing, maintain battery voltage above 12V and do not operate the doors, air conditioning, or other high-power electrical equipment.
  • 5
    After completing the refresh, perform the 'System Configuration' (enter the correct Coding code), 'Sensor Zero Point Calibration' (longitudinal acceleration sensor and pressure sensor calibration), and 'Brake Line Bleeding' procedures.
  • 6
    If the software update fails, the fault code does not clear, or the code returns, install a new IPB assembly. Complete online matching, coding, and brake fluid filling and bleeding.
Real-World Cases
BYD DTC AI Analysis

Replaced IPB assembly with used unit; DTC U030000 now present.

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A 2021 Song PLUS DM-i had its IPB assembly replaced with a salvage unit after an accident. After installation, the ABS and ESC warning lights came on in the instrument panel with DTC U030000. Diagnosis revealed the salvage part came from a gasoline Song Pro with incompatible software. Technicians used VDS2000 to run the 'Replace ECU' procedure, performing online programming and writing the Song PLUS DM-i Coding. Pressure sensor calibration cleared the fault.
BYD DTC AI Analysis

Interrupted software update locked up the module

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During IPB software upgrade, loose USB connection on diagnostic tool interrupted programming. DTC U030000 could not be cleared afterwards, and IPB could not enter programming mode. Forced flash in Boot mode after power-down/sleep failed. Replaced IPB assembly. Use regulated power supply (14V/50A) before flashing. Do not rely solely on vehicle battery.
BYD DTC AI Analysis

Software verification failed after 12V battery discharge

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Vehicle sat for one month; battery voltage dropped to 8.5V. After jump-starting, the instrument cluster displayed 'Braking system fault' and the scan tool retrieved DTC U030000. Prolonged low voltage caused an EEPROM data checksum failure in the IPB. Performed a 'software reset' with the scan tool and reflashed the same software version. Fault code cleared and functions returned to normal without hardware replacement.
BYD DTC AI Analysis

CVN data lost after accident repair

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Replaced the gateway module and IPB following front-end collision repairs. Post-repair, DTC U030000 set and AEB failed. The new gateway module's CVN (configuration data) did not match the original vehicle, preventing the IPB from recognising the network configuration. Downloaded the original vehicle backup data via the BYD DMS system and reprogrammed both the gateway and IPB. Synchronised the network configuration to clear the fault.
Other Qin Plus 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.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.B110BDTC B110B indicates a fault in the internal air pump (sampling pump) of the PM2.5 air quality detector. This pump draws cabin or outside air into the PM2.5 sensor detection chamber, enabling the laser scattering sensor to measure real-time particulate matter concentration. The air conditioning controller (or BCM) sets this DTC upon detecting an open or short circuit in the pump drive circuit, or abnormal current caused by a seized pump motor. This fault disables the "Green Clean" system, causes the instrument cluster air quality display to read abnormally or disappear, and disables the automatic fresh air/recirculation switching function. It does not affect the vehicle powertrain or core thermal management functions.B173A1ADTC B173A1A indicates the right middle-row side airbag (typically located on the side of the right second-row seat or inside the C-pillar trim panel) igniter circuit resistance measures 0 Ω. In the Supplemental Restraint System (SRS), normal airbag igniter resistance ranges between 2.0 and 5.0 Ω. A resistance of 0 Ω indicates a short to ground or a short between circuit wires, preventing the Airbag Control Unit (ACU) from establishing a normal monitoring circuit. This safety-critical fault prevents the airbag from deploying during a collision, continuously illuminates the instrument panel SRS warning lamp, and may force the entire airbag system into fail-safe mode.B173BDTC B173B indicates an abnormal electric A/C compressor speed feedback signal or a communication fault between the compressor controller and the motor. In BYD new energy models (e.g., Tang, Song, Qin, and Yuan series), this DTC belongs to the HVAC subsystem within the Body Control system and specifically involves the electric compressor closed-loop control circuit. The ECU sets this DTC when the compressor controller (IPM) fails to receive a valid pulse signal from the Hall speed sensor for more than 3 continuous seconds, or when the deviation between the detected actual speed and the target commanded speed exceeds the calibrated threshold (typically >500 rpm). This fault forces the A/C system into fail-safe mode and stops compressor operation. Symptoms include a complete lack of cooling, intermittent cooling, or a sharp decrease in cooling performance. The instrument cluster A/C warning lamp may also illuminate. Prolonged operation with this fault can degrade high-voltage system insulation or cause controller overcurrent damage.
Common problems reported for Qin Plus →Qin Plus overview →
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.