AU
C006202

DTC C006202 indicates the IPB (Intelligent Integrated Braking System) detected an abnormal longitudinal acceleration sensor signal — Seal U

Braking System

DTC C006202 indicates the IPB (Intelligent Integrated Braking System) detected an abnormal longitudinal acceleration sensor signal.

This sensor measures the vehicle’s longitudinal acceleration (deceleration) G-value.

It provides a key input signal for the coordinated control of Electronic Stability Control (ESC), the Anti-lock Braking System (ABS), Automatic Emergency Braking (AEB), and the energy recovery system.

BYD DMi models typically integrate this sensor within the IPB assembly or mount it on the chassis as an independent inertial sensor.

A signal fault causes these safety systems to enter a degraded mode or fail, affecting driving stability, particularly during emergency braking and handling on slippery roads.

The C006202 fault code on the Seal U indicates an abnormal longitudinal acceleration sensor signal in the Intelligent Integrated Braking System. This is a medium-severity issue because it can degrade ESC, ABS, AEB, and energy recovery functions. Common causes include an internal IPB sensor fault or damaged/poor wiring connections. The recommended fix is to visit an authorised dealer for diagnosis and repair. Typical repair cost data is available from recorded cases.
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Cases Logged
5
Causes
Likely Causes — Seal U
  • 1IPB assembly internal longitudinal acceleration sensor hardware fault (chip damage, cold solder joint, or aging drift)
  • 2Poor contact, open circuit, or short circuit in the sensor power supply, ground, or signal wiring (especially chassis wiring harness damage after wading or bottoming out).
  • 3Outdated IPB control unit software version or missing calibration data causes abnormal signal processing.
  • 4Vehicle collision or severe chassis impact shifted the sensor mounting position or damaged the internal micro-mechanical structure.
  • 5Extreme temperatures or electromagnetic interference cause the sensor signal to momentarily exceed tolerance limits, triggering the fault code.
What To Do
  • 1
    Use VDS or the BYD dedicated diagnostic tool to read all fault codes and freeze frame data. Check for accompanying DTC C006164 (lateral acceleration) or other IPB-related fault codes. Verify the longitudinal acceleration live data reads within ±0.1G while the vehicle is stationary.
  • 2
    Visually inspect the IPB assembly and chassis wiring harness connectors (especially the G03 connector under the vehicle) for water ingress, oxidation, loose connections, or mechanical damage. Measure the sensor supply voltage (typically 5V or 12V, depending on the specific model year) and the signal wire resistance.
  • 3
    Perform longitudinal acceleration sensor zero-point calibration: Access IPB system special functions via the diagnostic tool and select "Longitudinal Acceleration Sensor Zero-Point Calibration". Park the vehicle on a level surface, center the steering wheel, and follow the prompts to complete the learning procedure (some models require automatic learning while driving).
  • 4
    If calibration fails, disconnect the battery negative terminal for 5 minutes, clear the fault code, and cycle power for a self-test. If the fault returns, verify the IPB ground point (located in the front compartment or chassis side member) is secure. If necessary, sand the ground point and apply conductive paste.
  • 5
    Replace the IPB assembly: If diagnostics confirm an internal sensor fault (integrated design), replace the entire IPB brake master cylinder assembly. After replacement, bleed the system, perform calibration and longitudinal acceleration sensor zero-point learning, then perform a road test to verify ABS/ESC functions.
Real-World Cases
BYD DTC AI Analysis

BYD Song Plus DM-i ESC warning light on after water wading, C006202 intermittent

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A 2021 Song PLUS DMi with 20,000 km showed intermittent ABS and ESC warning lights after the owner drove through heavy rain and floodwater. The scan tool logged current fault code C006202. Live data showed the longitudinal acceleration signal fluctuating between 0.5G and 1.2G (normal: 0±0.1G). Raising the vehicle on a hoist revealed water stains and green corrosion inside the chassis IPB harness connector G03. We cleaned the connector, applied insulating silicone grease, dried the harness internals with compressed air, and reconnected it. The fault cleared. Check underbody sealing and fit a harness protective sleeve if required.
BYD DTC AI Analysis

C006202 persists after accident repairs; replace the IPB.

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After replacing the front bumper and underbody shields during accident repairs, the dashboard displayed 'Braking System Fault'. Scanned DTC C006202; it would not clear. Inspection found the IPB assembly sustained minor impact in the collision. Externally undamaged, but the internal longitudinal acceleration sensor MEMS chip had failed. Data stream showed longitudinal acceleration fixed at 2.4G regardless of vehicle movement. Since the sensor is integrated in the IPB and not available separately, replaced the IPB assembly and performed longitudinal acceleration zero-point calibration. Fault resolved.
BYD DTC AI Analysis

Software fault caused signal drift; upgraded IPB software to resolve.

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A 2022 Song Pro DMi frequently triggered DTC C006202 during normal driving on flat roads. Checks of the wiring harness and sensor data stream showed no obvious abnormalities; the code cleared but returned after 10 km. BYD technical service bulletins confirmed an IPB control unit software defect in this VIN range, causing abnormal longitudinal acceleration signal filtering. Fix: Upgrade the IPB control unit software using VDS2000 to the latest version (must be newer than the March 2023 release), then perform sensor zero-point learning. The fault did not recur after a 30 km road test.
BYD DTC AI Analysis

Aftermarket underbody shield pinched wiring harness, causing interference

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After the owner had an engine undershield fitted at a non-authorised workshop, the ESC warning light came on. Diagnosis revealed active DTC C006202. Inspection showed the installer had not torqued the aftermarket shield to specification; its edge compressed the IPB longitudinal acceleration sensor harness, causing the signal wire to short intermittently to ground. The technician repositioned the shield, fitted rubber buffer pads between the shield and harness, and repaired the crushed insulation to clear the fault. Technicians should note the impact of underbody modifications on chassis wiring.
BYD DTC AI Analysis

Sensor zero-point lost after extended storage; recalibrated

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A Song PLUS DM-i parked for three months displayed DTC C006202 and a "Check Brake System" warning upon restart. The vehicle had no collision or water ingress history, and wiring inspection found no faults. Prolonged 12V battery depletion caused the IPB control unit to lose its stored longitudinal acceleration zero-point calibration data. Repair: Connected a diagnostic tool, accessed the IPB system, and performed "Longitudinal Acceleration Sensor Zero-Point Calibration." Completed the calibration as prompted, cleared the DTC, road-tested with hard acceleration and hard braking, confirmed normal ESC operation, and delivered the vehicle.
Other Seal U Fault Codes
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.B110A02DTC B110A02 indicates the thermal management master control unit (HVAC ECU) or body control module (BCM) failed to receive valid CAN data frames from the PM2.5 air quality sensor over consecutive communication cycles (typically 500ms per cycle). The sensor typically mounts at the HVAC unit air inlet or behind the glove box and transmits real-time particulate concentration data (unit: μg/m³) to the HVAC controller via the CAN bus. The fault is essentially a communication link layer timeout. Potential causes include physical layer wiring faults, sensor power supply failures, sensor internal MCU lockup, or CAN network topology damage. Although this non-critical fault does not directly affect driving safety, it disables the intelligent air purification strategy and the automatic fresh air/recirculation switching function. In extreme cases, it triggers a thermal management system degraded mode, limiting compressor power or fixing the air flap position.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.B173712DTC B173712 indicates a short to power in the firing circuit of the right second-row side airbag module in the Supplemental Restraint System (SRS). Specifically, the "right second-row side airbag" typically refers to the side impact airbag located in the right B-pillar or the side of the right seat. The "12" suffix indicates a circuit short to battery positive (B+). This fault causes the following conditions: 1) The airbag may fail to ignite and deploy during a collision, resulting in a loss of side impact protection. 2) In extreme cases, unintended triggering may cause accidental airbag deployment. 3) The SRS control unit detects abnormally high circuit voltage (typically above 4.5V) and enters fault protection mode. This may disable the entire airbag system and continuously illuminate the instrument cluster airbag warning light.
Common problems reported for Seal U →Seal U 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.