AU
C053C76

DTC C053C76 indicates the IPB (Intelligent Integrated Braking System) detects a wheel speed sensor output signal exceeding the system's defined logical range — Seal 6 EV

Braking System

DTC C053C76 indicates the IPB (Intelligent Integrated Braking System) detects a wheel speed sensor output signal exceeding the system's defined logical range.

This fault is a signal anomaly that may manifest as: 1) Signal frequency/amplitude exceeding physical limits (e.g., vehicle speed above 300 km/h or below 0 with signs of movement); 2) Abnormal signal transition rate (e.g., instantaneous drop from 100 km/h to 0); 3) Signal distortion caused by sensor output noise interference.

This fault limits or disables safety functions including ABS, ESC, and automatic emergency braking.

The IPB system enters degraded protection mode and illuminates multiple warning lights on the instrument cluster.

5
Cases Logged
5
Causes
Likely Causes — Seal 6 EV
  • 1Incorrect wheel speed sensor installation direction (swapped left and right or reversed front and rear, causing reversed signal polarity or phase errors; relatively common on BYD Song PLUS DM-i models)
  • 2Abnormal gap between the sensor and the magnetic encoder (tone ring) (excessive gap causes a weak signal, insufficient gap causes friction damage, or impact during installation causes a position shift)
  • 3Magnetic encoder surface dirty or damaged (iron filings or mud/sand buildup causing signal distortion, or encoder scratches or missing teeth).
  • 4Sensor wiring harness open circuit, short circuit, or poor connector contact (especially where the chassis wiring harness routes past moving suspension components, as long-term vibration causes chafing or intermittent contact)
  • 5Wheel hub bearing magnetic encoder demagnetized or damaged (causing output signal amplitude to remain consistently low and fall outside the system recognition threshold)
What To Do
  • 1
    Use the VDS2000 diagnostic tool to read the complete fault codes and freeze frame data, and determine the specific faulty wheel position (left front/right front/left rear/right rear) and the vehicle speed when the fault triggered.
  • 2
    Raise the vehicle and visually inspect the wheel speed sensor installation on the affected wheel: confirm the installation direction is correct (the chamfered face of the sensor head matches the wheel rotation direction) and check the fixing bolt torque (typically 8-12 N·m).
  • 3
    Inspect the surface condition of the magnetic encoder (integrated into the wheel hub bearing inner ring or the back of the brake disc): remove iron debris and oil residue, and check for scratches, cracks, or missing teeth.
  • 4
    Measure sensor resistance: Disconnect the connector and measure the resistance between the two sensor terminals. The normal range is approximately 1.0-1.5 kΩ (at 20°C). Infinite resistance indicates an open circuit; excessively low resistance indicates a short circuit.
  • 5
    Use an oscilloscope to check the output signal: Rotate the wheel and verify the sine wave is continuous and the amplitude is normal (typically peak-to-peak >100mV). Check for noise or interruptions.
  • 6
    Perform a swap test: Swap the faulty side sensor with the normal side sensor, clear the fault code, and road test the vehicle. If the fault transfers with the sensor, replace the sensor. If the fault remains in the original position, check the wiring harness or bearing.
  • 7
    Check the IPB system software version. Early versions contain a signal processing algorithm defect. Update to the latest software version.
  • 8
    After repairing or replacing the faulty component, clear the fault code and perform a road test (including acceleration, deceleration, turning, and other driving conditions) to confirm the fault code does not recur and all systems operate normally.
Real-World Cases
BYD DTC AI Analysis

Song Plus DM-i left rear wheel speed sensor fitted backwards causing C053C76

✓
The vehicle entered the workshop with the dash displaying 'Check Brake System'. Scanned the system and retrieved DTC C053C76 (left rear wheel speed out of range). Found the left rear wheel speed sensor installed with incorrect orientation; the chamfer on the sensor head faced opposite to wheel rotation, inverting the sine wave signal phase so the IPB system could not recognise it. Reinstalled the sensor in the correct orientation (chamfer facing the direction of tyre forward rotation), clearing the fault. This fault commonly occurs after sensor replacement at repair shops; pay attention to the installation direction markings.
BYD DTC AI Analysis

Metal debris on magnetic encoder causes intermittent out-of-range signal

✓
Owner reported the ESC warning light occasionally comes on. Scan tool read historical fault code C053C76 (right front wheel). Checked the right front wheel speed sensor and wiring harness; both normal. Removed the brake disc and found the magnetic encoder surface covered in iron filings from brake pad wear, causing abnormal magnetic flux variations. The output signal showed spike pulses that read as out-of-range. Cleaned the filings from the magnetic encoder surface and sensor head, wiped with alcohol, reassembled and road tested. The fault did not recur.
BYD DTC AI Analysis

Chassis wiring harness wear caused wheel speed signal short circuit

✓
Dashboard warning triggered on rough roads. Scanned DTCs C053C76 (right rear wheel) and C053D00. Inspected the right rear wheel speed sensor harness and found the insulation worn through at the suspension arm mounting bracket, with internal wires contacting body metal and causing an intermittent short. When the chassis flexed, the short pulled the signal voltage low; the system flagged wheel speed as out of range (too low). Repaired the harness by re-wrapping, adjusting the routing, and adding a protective sleeve. Fault resolved.
BYD DTC AI Analysis

Wheel Bearing Magnetic Encoder Damage and Replacement Case

✓
After accident repairs (left rear wheel hub bearing replacement), a C053C76 fault appeared. Inspection found the replacement aftermarket wheel hub bearing had a defective integrated magnetic encoder. The encoder had uneven magnetic pole distribution, causing excessive output signal amplitude fluctuation during rotation; peaks exceeded the IPB system threshold. After installing a genuine wheel hub bearing, oscilloscope comparison showed the genuine unit produced a smooth, regular waveform. The fault code cleared and has not returned.
BYD DTC AI Analysis

IPB False Alarm Fixed with Software Update

✓
Multiple Song PLUS DM-i units reported C053C76 faults during low-speed (10-20km/h) cornering. Wheel speed sensors, wiring harnesses, and bearings checked normal; signal waveforms verified standard. Diagnosis: IPB controller software below V1.2 contains a flawed algorithm for processing low-speed differential signals, misinterpreting normal wheel speed variance as out-of-range. Software upgrade to V1.5 eliminated the fault.
Other Seal 6 EV 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.