AU
C080001

For BYD new energy vehicles (specifically E5, Qin, Tang, and Song models equipped with Bosch or Continental ESP systems), DTC C080001 indicates a fault in the ESP (Electronic Stability Program) lateral acceleration sensor or its power supply circuit — Seal U

Braking System

For BYD new energy vehicles (specifically E5, Qin, Tang, and Song models equipped with Bosch or Continental ESP systems), DTC C080001 indicates a fault in the ESP (Electronic Stability Program) lateral acceleration sensor or its power supply circuit.

Although the fault description reads "voltage below range", this specifically means the lateral acceleration sensor supply voltage falls below the ECU threshold (normal range: 4.5V–5.5V), or the sensor output signal voltage remains below the valid range (0.5V–4.5V).

Consequently, the ECU cannot obtain accurate vehicle lateral acceleration data.

This condition causes active safety functions (ESP, ABS, EBD) to fail or enter a degraded mode, severely compromising vehicle stability during cornering or driving on wet and slippery surfaces.

4
Cases Logged
5
Causes
Likely Causes — Seal U
  • 1Internal short circuit or damage in the lateral acceleration sensor causes excessive operating current and pulls down the supply voltage.
  • 25V reference voltage output circuit fault in the ESP control unit (or internal ECU of the ABS hydraulic modulator), unable to provide a stable sensor power supply.
  • 3Oxidation, looseness, or terminal back-out at the sensor wiring harness connector causes excessive contact resistance, reducing the actual voltage at the sensor.
  • 4Chassis impact or bottoming out causing a shifted sensor mounting position, or a damaged or shorted wiring harness.
  • 5Low battery voltage or poor body ground causes low operating voltage for the entire ABS/ESP system.
What To Do
  • 1
    Use a diagnostic tool to read the DTC freeze frame and confirm parameters such as vehicle speed and voltage at the time of the fault. Check the battery voltage and charging system for normal operation. Verify the static voltage is greater than 12.4V.
  • 2
    Check the power supply (terminal 30), ground (terminal 31), and ignition switch-controlled power (terminal 15) at the ESP control unit (typically located in the engine compartment or cabin). Verify the voltage is above 12V and the ground resistance is less than 1Ω.
  • 3
    Locate the lateral acceleration sensor (usually integrated into the ESP control unit or located beneath the chassis center tunnel). Check the wiring harness connector for looseness, water ingress, or oxidation. Measure the sensor supply voltage (should be 5V±0.25V).
  • 4
    If the power supply is normal, use the diagnostic tool to perform the sensor calibration procedure. If calibration fails or the data stream shows an abnormal acceleration value (approximately 0m/s² when stationary, range ±0.1m/s²), replace the lateral acceleration sensor or the ESP control unit assembly.
  • 5
    After replacing the component, clear the fault code, perform sensor Zero Point Calibration, and conduct a road test at different speeds (20km/h, 40km/h, 60km/h) to confirm normal ESP function and no fault code recurrence.
Real-World Cases
BYD DTC AI Analysis

BYD Qin 2015 — Workshop Manual Standard Diagnostic Procedure

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ESP warning light stays on, DTC C080001. Scan tool live data shows lateral acceleration sensor signal voltage at 0.2V (normal: approx. 2.5V at standstill). Further inspection revealed an internal 5V voltage regulator circuit failure in the ESP control unit. The faulty regulator could not provide stable power to the sensor, causing supply voltage to drop to only 3.2V (below the 4.5V threshold). Replaced the ESP hydraulic modulator assembly (integrated ECU and sensor), performed sensor calibration and yaw rate sensor calibration using the scan tool, cleared the fault codes, and road tested with normal results.
Original source ↗
BYD DTC AI Analysis

BYD Tang DM 2018 — Underbody scrape caused wiring harness fault

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ESP warning light illuminated after driving on rough roads, logging intermittent DTC C080001. Raised the vehicle and found stone damage to the lateral acceleration sensor wiring harness (located near the chassis crossmember). The damaged insulation caused intermittent short-to-ground between the internal conductor and body, pulling down the sensor supply voltage. Measured voltage between pin 1 (supply) and pin 3 (ground) at the sensor connector using a multimeter; voltage dropped from 5V to 2V when the vehicle shook. Repaired the wiring (replaced 30cm harness section), rewrapped with waterproof tape, and secured the harness routing. Fault resolved.
BYD DTC AI Analysis

BYD E5 2019 – Oxidised connector, poor contact

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Vehicle developed an ESP fault after wading through water. Scan tool showed active code C080001. Disconnected the lateral acceleration sensor connector under the cabin floor and found severely oxidized pins with green corrosion. Contact resistance measured 8Ω (normal <1Ω). Sensor supply voltage was only 3.8V. Cleaned the male and female terminals with electronic contact cleaner, applied dielectric grease to prevent further oxidation, and reconnected. Supply voltage returned to 5.02V. Cleared the fault codes; system normal.
BYD DTC AI Analysis

2017 BYD Song – False warning after tyre replacement

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After tyre replacement at an independent workshop, the dashboard threw an ESP fault. The scan showed C080001 and C080002 (longitudinal acceleration sensor). Inspection found the lift points had crushed the sensor harness at the centre of the chassis when technicians jacked up the car, damaging the wires inside without fully severing them. The sensor supply line measured 5 V static, but dropped to zero when cornering—chassis flex stretched the harness and opened the circuit. Replaced the damaged harness section and rerouted it clear of the lift points.
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.