AU
C006108

DTC C006108 indicates an abnormal signal from the lateral acceleration sensor (AY sensor) in the Electronic Stability Program (ESP) system — Seal U

Braking System

DTC C006108 indicates an abnormal signal from the lateral acceleration sensor (AY sensor) in the Electronic Stability Program (ESP) system.

The ESP Hydraulic Electronic Control Unit (HECU) typically houses this sensor to monitor the vehicle’s lateral acceleration (lateral G-force) in real time.

The sensor provides a key input for the ESP to calculate vehicle dynamic attitude, sideslip tendency, and yaw rate correction.

The ECU triggers this fault upon detecting a sensor signal outside the calibrated range (e.g., 0.5-4.5V), excessive signal drift, intermittent interruptions, or logical inconsistencies with yaw rate sensor or wheel speed sensor data.

This fault degrades or completely disables active safety functions such as ESP, ABS, and TCS, though the vehicle typically retains basic hydraulic braking.

On the E5 model, the lateral acceleration sensor and HECU feature an integrated design.

Do not replace the sensor separately; replace the complete HECU assembly.

5
Cases Logged
5
Causes
Likely Causes — Seal U
  • 1Internal lateral acceleration sensor hardware fault in the ESP Hydraulic Electronic Control Unit (HECU): sensor element aging, cold solder joints, or internal circuit damage causing abnormal signal output.
  • 2Wiring harness and connector faults: Water ingress or oxidation at the HECU connector (usually located near the engine compartment firewall), backed-out pins, harness wear causing short or open circuits, or vibration causing poor contact in the chassis harness.
  • 3Abnormal installation reference: Loose HECU retaining bolts, deformed mounting bracket, or failure to apply the standard torque (usually 25±5 N·m) after chassis accident repairs, causing the sensor mounting angle to deviate from the horizontal reference.
  • 4Electromagnetic interference or power supply quality issues: Aftermarket high-power electronic equipment (such as inverters or modified headlights) causes sensor supply voltage fluctuations (normally 12V ± 0.5V), or high-frequency interference affects the signal line.
  • 5Software calibration data lost: 12V battery disconnected for too long, outdated HECU software version, or failure to recalibrate sensor zero-point drift (calibrate the G sensor using VDS1000/2000).
What To Do
  • 1
    Preliminary diagnosis: Use the VDS diagnostic tool to read all fault codes and confirm if C006108 is a current DTC or a history DTC; record freeze frame data (vehicle speed, lateral acceleration, steering wheel angle, etc.); check the ABS/ESC warning light status on the instrument cluster.
  • 2
    Visual and installation inspection: Check the ESP hydraulic modulator (located on the left side of the firewall in the engine compartment) for physical damage and fluid leaks. Inspect the mounting bracket for deformation and verify the bolt torque meets specifications. Check the wiring harness connector (especially the 24-pin main connector) for water ingress, corrosion, and pin discoloration.
  • 3
    Electrical measurement: Disconnect the HECU connector and measure the voltage between the sensor power supply pin (usually 12V) and the ground pin (0V); measure the static voltage of the signal wire (usually 0.5-2.5V-4.5V, varying with acceleration); check the wiring harness insulation resistance to ground (should be >10MΩ).
  • 4
    Sensor calibration: If the wiring harness is normal, use the diagnostic tool to perform "G Sensor Calibration" or "Lateral Acceleration Sensor Zero-Point Calibration" (park the vehicle on level ground, center the steering wheel, switch off the ignition, and follow the prompts).
  • 5
    Replacement verification: If calibration fails or the fault persists, replace the ESP hydraulic modulator assembly (verify the spare part number against the VIN; for E5 models, this is usually an assembly with an ECU). After replacement, perform the following: ① Bleed the brake lines ② Calibrate the G-sensor ③ Calibrate the steering angle sensor ④ Perform a road test to verify ESP function.
  • 6
    Final verification: Clear all fault codes and perform a road test (including straight-line driving, lane changes, and figure-8 maneuvers). Confirm the lateral acceleration value in the scan tool data stream changes in real time with steering input (typically -1.5g to +1.5g), and the instrument cluster warning light remains off without recurrence.
Real-World Cases
BYD DTC AI Analysis

2018 E5: ESP warning light on after water wading, intermittent DTC C006108

✓
After driving through water, the dashboard ESC warning light illuminated intermittently. The scan tool read C006108 as a history code. Freeze frame data showed the lateral acceleration signal suddenly dropped to 0V at 40 km/h. Inspection found the ESP hydraulic modulator beneath the firewall had a degraded waterproof connector seal with water ingress. Repair: Cleaned the connector and applied conductive anti-corrosion grease, replaced the waterproof seal, and performed G-sensor calibration. Fault resolved. Recommend checking the chassis wiring harness protective sleeve sealing.
BYD DTC AI Analysis

2019 E5: C006108 active code after accident repair, ESP inoperative

✓
After front-left collision repairs, the dashboard ABS/ESC warning light stayed on constantly with DTC C006108 present and unable to be cleared. Inspection found the ESP assembly had been removed during the accident repair and reinstalled without being torqued to the standard 20N·m, and the mounting bracket was slightly deformed. Repair: Corrected the mounting bracket flatness, torqued the bolts to the standard 25N·m in a diagonal pattern, confirmed the sensor mounting base was level using a spirit level, then performed sensor calibration. Fault resolved.
BYD DTC AI Analysis

2018 E5: Intermittent C006108 after audio system modification

✓
After installing a high-power stereo and inverter, the ESC warning light flickered intermittently while driving. The scan tool showed DTCs C006108 and U0121 (ESP communication error). Inspection found the modified power harness bundled parallel to the ESP harness, causing electromagnetic interference. Resolution: Re-routed the modified wiring to maintain at least 30 cm clearance from the factory harness and fitted ferrite ring filters; with the vehicle restored to its original power supply configuration, the fault has not returned.
BYD DTC AI Analysis

Replaced HECU assembly on 2019 E5, but C006108 persists.

✓
Replaced the ESP hydraulic modulator assembly due to a spongy brake pedal, but could not clear DTC C006108. Live data showed lateral acceleration fixed at 2.3V without changing. Checked the new assembly—part number correct—but the G-sensor zero-point calibration hadn't been done after installation. Solution: Used VDS2000 to access 'ABS system - Special functions - G-sensor calibration', followed the prompts to complete level calibration (vehicle stationary on level surface, steering wheel centred). The fault code cleared automatically once calibration completed, and live data returned to normal.
BYD DTC AI Analysis

2018 E5: C006108 appeared after driving on rough roads; internal sensor fault.

✓
ESC warning light illuminated suddenly after the vehicle drove over a speed bump. Current DTC C006108. Live data showed lateral acceleration jumping from normal range (-0.1g to +0.1g) to +2.8g instantly during the fault. Wiring harness, connectors, and installation checked normal; supply voltage stable. Diagnosed as dry solder joint or component damage in HECU internal lateral acceleration sensor. Replaced ESP hydraulic modulator assembly (part number BC-3615010) and performed full calibration after installation. Fault completely eliminated.
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.