AU
U012608

DTC U012608 indicates the ABS/ESP control unit receives an abnormal CAN bus data frame or detects a checksum failure from the Steering Angle Sensor (SAS) — Atto 3

Braking System

DTC U012608 indicates the ABS/ESP control unit receives an abnormal CAN bus data frame or detects a checksum failure from the Steering Angle Sensor (SAS).

This fault is a communication data integrity error, not a simple signal timeout.

The ABS module flags "corrupted data" when it detects a CRC error in the SAS data packet, an abnormal Data Length Code (DLC), or a signal value outside the physically reasonable range.

This fault causes the vehicle's Electronic Stability Program (ESP), Traction Control System (TCS), and Automatic Emergency Braking (AEB) to enter a degraded mode or fail completely.

Some models trigger power limitation (limp mode), severely compromising driving safety.

The U012608 fault code on the Atto 3 indicates a medium-severity communication data error between the ABS/ESP control unit and the Steering Angle Sensor. It may be caused by a damaged sensor sending corrupted data, or by loose, oxidized, or water-damaged wiring connectors affecting CAN signals. ESP, traction control, and AEB may be reduced or disabled. Visit an authorised dealer for diagnosis and repair. Typical repair cost data is available.
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Cases Logged
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Causes
Likely Causes — Atto 3
  • 1Internal damage to the Steering Angle Sensor (SAS) causing transmission of incorrect data frames or signal drift.
  • 2Sensor wiring harness connector oxidized, loose, or corroded from water ingress (common in flooded or water-exposed vehicles), causing CAN signal transmission interference.
  • 3Chassis CAN bus (powertrain CAN) circuit short to ground, short to power, or poor connection, affecting data communication quality.
  • 4Sensor software version mismatch or missing calibration data prevents the ABS module from correctly interpreting sensor data.
  • 5Internal fault in the ABS/ESP control unit CAN receiver module prevents correct decoding of SAS data.
What To Do
  • 1
    Use the dedicated BYD diagnostic tool (VDS or EDT) to read all fault codes. Confirm if U012608 is a current or historical fault, and check for accompanying communication fault codes such as U010008 and U014004.
  • 2
    Inspect the appearance of the steering angle sensor under the steering wheel and the condition of the connector. Check the connector pins specifically for oxidation, backed-out pins, or signs of water ingress. Clean with electrical contact cleaner if necessary.
  • 3
    Test the sensor wiring harness: Disconnect the connector. Measure the voltage at pins 1-2 (power and ground); the voltage should be 12V/0V. Measure the voltage to ground for CAN-H (approx. 2.5-3.5V) and CAN-L (approx. 1.5-2.5V). Use an oscilloscope to verify the CAN waveform is regular.
  • 4
    Check the chassis CAN bus terminal resistance (standard value approx. 60 Ω; individual terminal resistor 120 Ω) and inspect the bus for short or open circuits.
  • 5
    If circuit measurements are normal, remove and replace the steering angle sensor assembly. Note: Do not use non-genuine parts. Sensor models may vary by vehicle configuration.
  • 6
    Use the dedicated diagnostic tool to perform the 'Yaw Rate and Steering Angle Position Sensor Calibration' procedure (BYD dedicated diagnostic tool required; generic diagnostic tools cannot complete this). Follow the prompts to complete steering wheel centering and angle learning.
  • 7
    Clear all fault codes and perform a road test to verify the ESP and ABS warning lights are off and the vehicle has no power limitation.
Real-World Cases
BYD DTC AI Analysis

Replaced damaged steering angle sensor assembly on BYD Song

✓
A BYD Song had the ESP and traction control warning lights on with no throttle response. Current DTC U012608 (Lost Communication With Steering Angle Sensor). Removed the steering wheel and checked the steering angle sensor connector on the column. Pins 1-2 had normal power and ground, ruling out wiring. Internal chip failure in the sensor was causing data frame errors. Replaced the sensor with an OEM unit and ran the calibration procedure in VDS. Fault cleared, ESP system normal.
Original source ↗
BYD DTC AI Analysis

Song MAX: Wiring Corrosion Repair on Flood-Damaged Vehicle

✓
A flood-damaged BYD Song MAX displayed "Please check ESP system" on the dash, the ESP warning light was on, and acceleration was weak. Retrieved fault codes U012608, P0228, P2122, and U010008; they returned soon after clearing. Inspection found severe oxidation and corrosion in multiple bus connectors in the engine bay and cabin. Cleaned the steering angle sensor connector and chassis CAN bus connection points, and repaired the damaged wiring harness. After the wiring repair, used a dedicated diagnostic tool to recalibrate the yaw rate system and steering angle position sensor (Launch X431 and Autel tools cannot complete this calibration). Fault completely resolved.
Original source ↗
BYD DTC AI Analysis

Song CAN bus and ECM communication fault

✓
While driving, the BYD Song's engine and ESP warning lights suddenly illuminated with limited power. DTCs U010008 (ECM CAN data corrupted) and U012608 were stored. The technician checked the CAN bus waveform with an oscilloscope and found noise indicating communication faults. Troubleshooting traced this to a poor connection in the CAN bus wiring. After repairing the connection, the technician checked and upgraded the ECM software and recalibrated the steering angle sensor. Power returned and the communication DTCs did not return.
Original source ↗
BYD DTC AI Analysis

Diagnostic tool compatibility issue and sensor calibration

✓
2020 BYD Song reported DTC U012608. A generic scan tool could not locate the fault or clear the code. The technician switched to a BYD-specific diagnostic tool and found the generic unit accessed incorrect vehicle configuration settings, causing false positives. Disconnect the battery negative terminal for five minutes to clear intermittent faults. For persistent faults, confirm the wiring is normal first, then perform steering angle sensor calibration using the dedicated diagnostic tool; otherwise the fault light stays on even after replacing the sensor.
Original source ↗
Other Atto 3 Fault Codes
P0AA6Hybrid Battery Voltage System Isolation FaultB1108For 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.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.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.B173A1ADTC B173A1A indicates the right middle-row side airbag (typically located on the side of the right second-row seat or inside the C-pillar trim panel) igniter circuit resistance measures 0 Ω. In the Supplemental Restraint System (SRS), normal airbag igniter resistance ranges between 2.0 and 5.0 Ω. A resistance of 0 Ω indicates a short to ground or a short between circuit wires, preventing the Airbag Control Unit (ACU) from establishing a normal monitoring circuit. This safety-critical fault prevents the airbag from deploying during a collision, continuously illuminates the instrument panel SRS warning lamp, and may force the entire airbag system into fail-safe mode.
Common problems reported for Atto 3 →Atto 3 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.