AU
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 — Seal 6 EV

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 Seal 6 EV indicates the IPB brake control unit software does not match the vehicle’s network configuration. This is a medium-severity braking system fault that may limit regenerative braking, AEB, ESC, or brake assist. Common causes include incorrect IPB software flashing or missing coding and synchronization after fitting a used IPB unit. Visit an authorised dealer for software matching and coding. Typical repair cost data is available.
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Cases Logged
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Causes
Likely Causes — Seal 6 EV
  • 1Incorrect IPB ECU software version (incorrectly flashed software package for a different vehicle model, model year, or trim level)
  • 2Failure to perform online matching, coding, and anti-theft synchronization after installing a salvaged or used IPB assembly.
  • 3Interrupted software flashing (battery voltage below 12V, unstable OBD connection, or diagnostic tool crash) corrupts the program block.
  • 4Vehicle network configuration data (CVN/AS-BUILT data) missing; inconsistent with gateway module configuration.
  • 5IPB internal EEPROM data corruption (due to prolonged battery discharge, strong electromagnetic interference, or hardware aging)
What To Do
  • 1
    Use VDS2000 or a BYD dedicated diagnostic tool to read fault codes. Confirm U030000 is a current fault, not a history fault. Record the current IPB software version number (e.g., BGM+ version number) 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 2.5V, dominant 3.5V/1.5V) to rule out software checksum errors caused by power supply fluctuations.
  • 3
    Check the vehicle VIN against the 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 Update": Connect the diagnostic tool to the BYD cloud server and download the latest IPB software package for the corresponding VIN (usually in .hex or .s19 format). Maintain battery voltage above 12V during flashing 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 value), 'Sensor Zero Point Calibration' (longitudinal acceleration sensor and pressure sensor calibration), and 'Brake Line Bleeding' procedures.
  • 6
    If the software flash fails, or the fault code will not clear or recurs, replace the IPB assembly with a new unit. Perform 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 Seal 6 EV 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.B1737DTC B1737 indicates the Supplemental Restraint System (SRS) detected abnormal continuity between the right middle-row side airbag squib circuit (typically the second-row right seat side airbag or right curtain airbag) and the vehicle power supply (B+, battery positive). The SRS ECU monitors the airbag inflator resistance via an internal current source (normal resistance: 2.0–3.0 Ω). If the ECU detects the voltage across the inflator circuit remaining close to battery voltage (>5 V and approaching 12 V) instead of the expected low potential or floating state, it identifies a short to power. This fault prevents the airbag from deploying normally during a collision because the short circuit bypasses the firing current. In extreme cases, abnormal current can cause unintended deployment, posing a severe safety hazard.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 Seal 6 EV →Seal 6 EV 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.