AU
C006B00

DTC C006B00 in the BYD IPB (Intelligent Integrated Brake) system indicates the Electronic Stability Program (ESP/ESC) activation time exceeds the designed safety threshold — Seal U

Braking System

DTC C006B00 in the BYD IPB (Intelligent Integrated Brake) system indicates the Electronic Stability Program (ESP/ESC) activation time exceeds the designed safety threshold.

This fault does not simply mean the system operated too long; it indicates the IPB control module detects vehicle stability control functions (including anti-skid, traction control, and yaw moment control) continuing to operate under non-essential conditions, or the system failing to exit the stability control state.

This typically points to signal drift, calibration errors, or wiring faults in inertial measurement units, such as the yaw rate sensor and longitudinal/lateral acceleration sensors.

These issues cause the IPB to misjudge the vehicle as continuously unstable.

This fault triggers IPB system degradation and may limit or disable functions such as ABS, ESP, and Automatic Emergency Braking (AEB), severely compromising driving safety.

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Cases Logged
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Causes
Likely Causes — Seal U
  • 1Signal drift, failure, or loose mounting of the yaw rate sensor (YRS) or longitudinal/lateral acceleration sensor causes the IPB to continuously receive incorrect vehicle dynamic attitude signals.
  • 2Abnormal internal software operation in the IPB intelligent integrated brake control module, an MCU processor fault, or an infinite loop in the low-level driver prevents the system from exiting stability control mode normally.
  • 3Sensor calibration procedure not performed after replacing the IPB assembly or repairing the suspension system, or calibration data lost during driving (occurs with calibration fault codes such as C051D01).
  • 4Poor connection, oxidized pins, or damaged shielding layer at the inertial sensor wiring harness connector causing signal interference; or abnormal communication on the CAN network (powertrain network) causing continuous data frame errors.
  • 5Vehicle modifications (such as installing non-OEM tires or additional electronic equipment) cause a logic mismatch between the wheel speed and inertial sensor signals, forcing the ESP system to continuously attempt corrections.
What To Do
  • 1
    Use the BYD VDS diagnostic tool to read the complete fault codes and freeze frame data. Check for accompanying fault codes such as C006A02 (yaw rate sensor signal), C006108/C006208 (acceleration sensor signal), and C051D01 (calibration error). Record key parameters at the time of the fault, such as vehicle speed, steering angle, and lateral acceleration.
  • 2
    Check the IPB intelligent integrated braking system power supply (constant power, IG power) and ground point (G08, G09, etc.) voltages, as well as the CAN-H/CAN-L line resistance (approx. 60Ω) and waveforms. Rule out system abnormalities caused by power supply fluctuations or communication faults.
  • 3
    Check the mounting condition of the yaw rate sensor and longitudinal/lateral acceleration sensors (usually integrated inside the IPB or installed separately near the vehicle center of gravity). Verify the mounting bolt torque (usually 8-10 Nm), mounting surface levelness, and wiring harness connector sealing. Inspect for water ingress and signs of impact.
  • 4
    Perform the IPB sensor calibration procedure: Use VDS to enter 'Intelligent Integrated Braking System' → 'Special Functions' → 'Sensor Calibration'. Follow the prompts to complete steering wheel center position learning, yaw rate zero-point calibration, and longitudinal/lateral acceleration zero-point calibration. Ensure the vehicle is stationary on a level surface.
  • 5
    If calibration fails or the fault recurs, check the IPB software version and perform a software upgrade if necessary (OTA or offline flashing). For confirmed hardware faults, replace the IPB intelligent integrated brake control assembly (e.g., part number BYD-3610100-XX). After replacement, recalibrate and perform a road test to verify the ESC function exits normally.
Real-World Cases
BYD DTC AI Analysis

Song PLUS DM-i: C006B00 caused by IPB replacement without calibration

✓
After replacing the IPB assembly during accident repairs, the instrument cluster displayed "Check ESP System". VDS retrieved DTCs C006B00 and C051D01. Inspection found the technician had not performed sensor calibration. Performed the VDS calibration procedure: entered IPB system → Special Functions → Sensor Calibration, completed steering wheel zero position, yaw rate, and longitudinal acceleration calibration, cleared the fault codes, and road tested. Fault resolved.
BYD DTC AI Analysis

Han EV yaw rate sensor signal drift causes stability system to operate continuously

✓
The owner reported the ESP warning light intermittently illuminated while driving. They felt the vehicle "dragging" despite not braking. VDS detected DTCs C006B00 and C006A02. Inspection found the yaw rate sensor integrated in the IPB had signal drift; data showed 0.5°/s yaw rate with the vehicle stationary. Replaced the IPB assembly and calibrated. Fault resolved.
BYD DTC AI Analysis

Qin PLUS DM-i inertial sensor wiring harness poor contact

✓
After driving on rough roads, the dashboard warned. Retrieved DTC C006B00. Inspected the IPB wiring harness and found the connector lock on the front-compartment inertial sensor (mounted separately to the body rail) had broken, causing intermittent pin contact and signal interruption while driving. Replaced the wiring harness connector and reinforced the mounting bracket. Cleared the fault code; fault resolved.
BYD DTC AI Analysis

Outdated software caused ESP malfunction in BYD Tang DM-p

✓
Early IPB software versions had a logic flaw causing continuous ESP intervention during low-speed, large-angle steering. VDS reported code C006B00. Hardware inspection found no faults. Updated IPB software to version V2.3 or above via OTA. The revised control logic resolved the issue and the fault code has not returned.
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.