AU
C055600

DTC C055600 indicates the IPB (Intelligent Integrated Braking System) control module detects the hardware model or electrical characteristics of the right front wheel speed sensor do not match the system calibration parameters — Atto 3

Braking System

DTC C055600 indicates the IPB (Intelligent Integrated Braking System) control module detects the hardware model or electrical characteristics of the right front wheel speed sensor do not match the system calibration parameters.

This is a configuration/calibration fault, not a simple signal fault.

By monitoring the sensor resistance, signal voltage range, pulse characteristics, or digital communication protocol, the IPB system detects the installed sensor does not match the vehicle configuration code (VIN-corresponding calibration data).

This typically occurs after installing non-genuine parts, installing a sensor from another vehicle model, or if the sensor does not match the wheel hub bearing assembly (some BYD models separate the magnetic encoder bearing from the sensor).

When this fault triggers, the IPB enters degraded mode, disables ABS, ESC, Automatic Emergency Braking (AEB), and energy recovery functions, retaining only basic hydraulic braking.

The C055600 fault code on the Atto 3 indicates a medium-severity calibration mismatch in the right front wheel speed sensor detected by the IPB braking system. It is often caused by a non-genuine or incorrect sensor, or a wheel hub bearing/encoder ring that does not match the vehicle calibration. ABS, ESC, AEB, and energy recovery may be disabled. Visit an authorised dealer to confirm parts and recalibrate or replace them. Typical repair cost data is available.
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Cases Logged
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Causes
Likely Causes — Atto 3
  • 1Non-genuine aftermarket wheel speed sensor installed with resistance or signal characteristics that do not match factory calibration (genuine part is typically a 1200-1600Ω active sensor; mistakenly installed 800-1200Ω passive sensor).
  • 2Mistakenly installing a part from another model during right front wheel hub bearing assembly replacement causes a magnetic encoder ring pole count or spacing mismatch (for example, installing a 46-pole Song Pro magnetic ring instead of the required 48-pole Song PLUS DMi magnetic ring).
  • 3The IPB control module software version is outdated and fails to recognize the new sensor's communication protocol (common in 2021 Song PLUS DM-i models combining early software versions with later, improved replacement sensors).
  • 4Incorrect sensor wiring harness connector pinout or mismatched connector type (e.g., mistakenly connecting an active sensor to a passive wiring harness circuit, causing a power supply voltage mismatch)
  • 5Failure to perform the IPB system sensor configuration writing (coding) or parameterization process after unauthorized vehicle repairs.
What To Do
  • 1
    Use the VDS2000/VDS3000 diagnostic tool to access the IPB system and read the freeze frame data. Verify the deviation range of the sensor signal voltage and resistance from the calibrated values when the fault occurred.
  • 2
    Raise the vehicle. Check the right front wheel speed sensor part number (usually stamped on the sensor body). Verify the part number against the EPC system to confirm it matches the vehicle configuration code (e.g., Song PLUS DMi requires the 5A-36301-XX series active sensor).
  • 3
    Remove the sensor and measure the resistance. Normal values are 1.2-1.6kΩ for an active sensor (Hall type) and 0.8-1.2kΩ for a passive sensor (electromagnetic type). If the resistance is out of specification, replace the sensor with a genuine part.
  • 4
    Check the wheel hub bearing magnetic encoder ring: Measure the sensor signal using an oscilloscope. Rotate the wheel and observe the number of waveform cycles (Song PLUS DM-i should output 48 pulses per revolution). If the pulse count is incorrect, replace the bearing assembly.
  • 5
    If hardware is normal, perform the IPB system 'Sensor Parameterization' procedure: enter Special Functions → Wheel Speed Sensor Configuration → select the correct sensor model code (Active/Passive and number of poles) → write to IPB EEPROM.
  • 6
    After completing the configuration, perform 'Steering Angle Sensor Calibration' and 'Yaw Rate Sensor Calibration' (due to IPB system linkage). Clear the fault codes and perform a road test to confirm ABS/ESC function restoration and no fault code recurrence.
Real-World Cases
BYD DTC AI Analysis

Song PLUS DMi: Aftermarket sensor replacement caused ESC failure

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2021 BYD Song PLUS DM-i, 32,000 km, dashboard showing ABS and ESP warning lights. VDS read C055600 (right front wheel speed sensor wrong model). Found an independent shop had replaced the right front wheel bearing with a branded aftermarket part (no magnetic encoder ring). The factory unit integrates a 48-pole magnetic encoder ring. Installed genuine BYD hub bearing assembly (PN SA3E-3103200) and ran sensor parameterization. Fault cleared.
BYD DTC AI Analysis

IPB software version mismatch causes false alarm

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BYD Song PLUS DM-i 2021. Vehicle came in for maintenance and stored DTC C055600. Confirmed the sensor was OEM and measured 1.4 kΩ resistance (normal). Found IPB control module software version 2021.08, though the vehicle had received an upgraded 2022-model wheel speed sensor under warranty (minor resistance characteristic differences). Updated IPB software to version 2022.12 and performed sensor recalibration. Fault cleared.
BYD DTC AI Analysis

Aftermarket wiring harness modification caused abnormal sensor power supply

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After sheet metal repairs to the right front fender following an accident, the vehicle set DTC C055600. Inspection found technicians had re-soldered the wiring harness during the crash repair and mistakenly connected the active wheel speed sensor power supply line (which requires 12V) to the 5V reference voltage line. This caused insufficient sensor output signal amplitude. Corrected the harness connections to restore the 12V power supply circuit and cleared the fault code.
BYD DTC AI Analysis

Wrong sensor models fitted to left and right sides (DM-i and EV variants mixed)

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While servicing both vehicles simultaneously, the technician mistakenly installed the EV's right front wheel speed sensor (passive, 900Ω) on the DMi. The DMi's IPB system expects an active sensor; startup self-test detected abnormal resistance and set C055600. Replaced the sensor with the DMi-specific active unit (1.5kΩ) and cleared the fault code. Resolved.
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.