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 — Qin Plus

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.

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Cases Logged
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Causes
Likely Causes — Qin Plus
  • 1Installed a non-genuine aftermarket wheel speed sensor with a resistance value or signal characteristics that do not match factory calibration (original is usually a 1200-1600Ω active sensor; mistakenly installed an 800-1200Ω passive sensor).
  • 2Installing an incorrect part from another model during right front wheel hub bearing assembly replacement, causing a mismatch in the magnetic encoder ring pole count or spacing (e.g., mistakenly installing a 46-pole ring from the Song Pro when the Song PLUS DMi requires a 48-pole magnetic ring).
  • 3Outdated IPB control module software fails to recognize the new sensor's communication protocol (commonly occurs on 2021 Song PLUS DM-i models when early software pairs with a later improved replacement sensor).
  • 4Incorrect sensor harness connector pinout or mismatched connector type (e.g., incorrectly connecting an active sensor to a passive harness circuit, causing a supply voltage mismatch)
  • 5Failure to perform the IPB system sensor configuration writing (Coding) or parameterization procedure 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 values from the calibrated values when the fault occurred.
  • 2
    Raise the vehicle and 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. The normal value is 1.2-1.6 kΩ for an active sensor (Hall type) and 0.8-1.2 kΩ 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: Use an oscilloscope to measure the sensor signal. Rotate the wheel and observe the number of waveform cycles (the Song PLUS DMi should output 48 pulses per revolution). If the pulse count is incorrect, replace the bearing assembly.
  • 5
    If the 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 integration). Clear the fault codes and road test the vehicle to confirm ABS/ESC functions operate correctly and no fault codes recur.
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 Qin Plus 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.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.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.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.B173BDTC B173B indicates an abnormal electric A/C compressor speed feedback signal or a communication fault between the compressor controller and the motor. In BYD new energy models (e.g., Tang, Song, Qin, and Yuan series), this DTC belongs to the HVAC subsystem within the Body Control system and specifically involves the electric compressor closed-loop control circuit. The ECU sets this DTC when the compressor controller (IPM) fails to receive a valid pulse signal from the Hall speed sensor for more than 3 continuous seconds, or when the deviation between the detected actual speed and the target commanded speed exceeds the calibrated threshold (typically >500 rpm). This fault forces the A/C system into fail-safe mode and stops compressor operation. Symptoms include a complete lack of cooling, intermittent cooling, or a sharp decrease in cooling performance. The instrument cluster A/C warning lamp may also illuminate. Prolonged operation with this fault can degrade high-voltage system insulation or cause controller overcurrent damage.
Common problems reported for Qin Plus →Qin Plus 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.