AU
C051400

This DTC indicates the IPB (Intelligent Integrated Braking System) detects an abnormally low-resistance connection between the right rear wheel speed sensor power supply circuit (typically a 12V or 5V reference voltage) and body ground (GND), constituting a short to ground — Atto 8

Braking System

This DTC indicates the IPB (Intelligent Integrated Braking System) detects an abnormally low-resistance connection between the right rear wheel speed sensor power supply circuit (typically a 12V or 5V reference voltage) and body ground (GND), constituting a short to ground.

In the BYD IPB system, the wheel speed sensor is a two-wire active Hall sensor.

The ECU supplies operating voltage to the sensor via the power supply line.

A short to ground on the power supply line causes: 1) complete loss of the right rear wheel speed signal; 2) the IPB system to trigger limp mode, automatically disabling the dynamic functions of the ABS, ESC, Automatic Emergency Braking (AEB), and Electronic Parking Brake (EPB); 3) potential damage to the internal IPB driver circuit if the short-circuit current is excessive.

This is a hard-wire circuit fault, not signal interference or performance degradation.

Repair the fault immediately to prevent braking system failure.

The C051400 fault code on the Atto 8 indicates a high-severity short to ground in the right rear wheel speed sensor power supply circuit. This can disable the wheel speed signal and affect ABS, ESC, AEB, and EPB functions. Common causes include damaged sensor wiring rubbing on suspension parts or an internally shorted wheel speed sensor. Visit an authorised dealer promptly for diagnosis and repair. Typical repair cost data is available from recorded cases.
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Cases Logged
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Causes
Likely Causes — Atto 8
  • 1Right rear wheel speed sensor wiring harness insulation damage: Stones striking the vehicle chassis during driving break the harness sheath, or loose harness retaining clips cause long-term friction against suspension components, exposing the power supply wire copper core and causing it to contact metal body parts.
  • 2Wheel speed sensor internal short circuit: Breakdown of the internal Hall element or capacitor causes continuity between the power supply terminal and the sensor housing (ground). Common causes include sensor aging, overheating, or manufacturing defects.
  • 3Wiring harness connector water ingress and corrosion: Wading in the right rear wheel area or direct high-pressure spraying during car washing causes the sensor plug seal to fail. This forms an electrolyte conductive path between the pins, causing a short circuit between the power supply pin and the ground pin.
  • 4IPB control module internal drive circuit fault: The constant current source or voltage regulator chip inside the IPB module supplying power to the wheel speed sensors breaks down, causing the output terminal to short to ground. This fault typically causes multiple wheel speed sensors to simultaneously report power supply short-circuit fault codes.
  • 5Harness damage caused by accident or modification: The vehicle suffered a right-rear collision and improper routing during repair pinched the harness; or fixing screws pierced the harness during aftermarket installation of reversing sensors, mud flaps, or other components.
What To Do
  • 1
    Safety preparation and fault confirmation: Use VDS or a dedicated diagnostic tool to read all fault codes; confirm if C051400 appears alone or with related wheel speed signal faults; inspect the right rear wheel speed sensor connector for looseness, backed-out pins, or corrosion; verify the vehicle is stationary when the fault occurs (to rule out electromagnetic interference during driving).
  • 2
    Sensor body inspection: Disconnect the right rear wheel speed sensor connector. Use a multimeter to measure the resistance between the sensor-side power supply pin and the ground pin (or sensor metal housing). Normal resistance is greater than 10 MΩ (open circuit). If the resistance is less than 1 Ω, replace the right rear wheel speed sensor. Also measure the resistance between the sensor signal pin and the power supply pin. Normal resistance is 1-2 kΩ (Hall sensor internal resistance).
  • 3
    Harness continuity and insulation check: Keep the sensor connector disconnected. Locate the right rear wheel speed sensor power supply pin at the IPB module side (located in the engine compartment or cabin front bulkhead) and measure its resistance to ground. Normal resistance exceeds 10 MΩ. A reading of 0-5 Ω confirms a short to ground. Use a multimeter continuity buzzer to measure harness continuity section by section. Focus on bends where the harness passes through body sheet metal holes and near the suspension spring seat.
  • 4
    Short circuit location and repair: Upon confirming a wiring harness short circuit, progressively strip the harness sheath from the IPB module towards the wheel, focusing on the firewall grommet and rear wheel arch liner areas. After locating the damaged point: if the damage is minor (single wire damaged), apply a double layer of waterproof heat-shrink tubing for insulation; if multiple wires sustain damage or the copper core shows severe oxidation, replace the right rear wheel speed sensor wiring harness assembly (part number usually starts with CJ). Check and replace any damaged harness retaining clips. Maintain a minimum clearance of 20mm from moving parts.
  • 5
    IPB module verification and testing: If the wiring harness and sensor are normal, measure the output voltage at the corresponding IPB module pin (ignition switch ON, do not disconnect the connector). Normal voltage is battery voltage (12V) or a 5V reference voltage. If the module output terminal shorts to ground, replace the IPB assembly (requires coding and longitudinal acceleration sensor calibration). After repair, clear the fault codes and perform a road test (vehicle speed above 40km/h). Confirm the wheel speed data stream is normal and the fault code does not recur. Verify the ABS and ESC functions operate normally.
Real-World Cases
BYD DTC AI Analysis

Song PLUS DM-i right rear wheel speed sensor wiring harness chafed and shorted

✓
Dashboard displayed "Check ABS System" and "Automatic Emergency Braking Limited". VDS retrieved DTC C051400. Lifted the vehicle and found the RH rear wheel speed sensor harness chafed where it passes through the subframe. The internal power supply wire (red/black) had exposed copper contacting the subframe, causing a short to ground. Repair: Cut out the damaged section, crimped new waterproof terminals, sealed with double-layer heat shrink tubing, rerouted the harness and added corrugated tubing protection. Fault resolved.
BYD DTC AI Analysis

Right rear wheel speed sensor connector corroded and shorted after driving through water

✓
Owner reported multiple dashboard warning lights after driving through heavy rain and floodwater. Diagnosis revealed DTCs C051400 and C051100 (similar fault for the right front wheel). Inspection found water inside the right rear wheel speed sensor connector; a conductive film between the power and ground pins measured only 0.3Ω. Disassembled the connector, cleaned it with anhydrous ethanol, dried it with an air gun, applied conductive grease, and replaced the waterproof seal. Cleared the fault codes; they did not return.
BYD DTC AI Analysis

Damage to the IPB internal driver chip shorted the power supply to multiple wheel speed sensors.

✓
Accident-repaired vehicle (right rear previously impacted). Replaced right rear wheel speed sensor and wiring harness; C051400 persisted. Further inspection found the MOSFET inside the IPB module that supplies power to the right rear wheel had shorted internally, with the output shorted to ground. Voltage at the right rear wheel speed sensor connector measured 0V (nominal 12V), and the corresponding pin at the IPB module connector also showed a short to ground. Solution: Replaced the IPB intelligent integrated brake system assembly and performed online configuration and sensor calibration.
BYD DTC AI Analysis

改装挡泥板固定螺丝刺穿线束

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用户自行加装后轮挡泥板后一周内出现故障。检查发现右后轮罩内衬新加装的自攻螺丝过长，直接穿透线束导致供电线与车身搭铁短路。修复措施：拆除螺丝，更换受损线束段，重新布设线束避开改装件安装位，使用原车预留的线束固定卡扣，教育用户避免在非标准位置打孔。
Other Atto 8 Fault Codes
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.B110A02DTC B110A02 indicates the thermal management master control unit (HVAC ECU) or body control module (BCM) failed to receive valid CAN data frames from the PM2.5 air quality sensor over consecutive communication cycles (typically 500ms per cycle). The sensor typically mounts at the HVAC unit air inlet or behind the glove box and transmits real-time particulate concentration data (unit: μg/m³) to the HVAC controller via the CAN bus. The fault is essentially a communication link layer timeout. Potential causes include physical layer wiring faults, sensor power supply failures, sensor internal MCU lockup, or CAN network topology damage. Although this non-critical fault does not directly affect driving safety, it disables the intelligent air purification strategy and the automatic fresh air/recirculation switching function. In extreme cases, it triggers a thermal management system degraded mode, limiting compressor power or fixing the air flap position.B110B07This fault code indicates abnormal operation of the internal air pump (sampling pump) in the PM2.5 air quality detection module. The PM2.5 detector uses the laser scattering principle to measure particulate concentration and requires a built-in air pump to draw ambient air into the detection chamber at a constant flow rate. The ECU sets this code when it detects an open or short in the air pump drive circuit, abnormal current (stall or free-running), or abnormal speed feedback. This fault causes the automatic air conditioning system to lose air quality sensing capability, preventing automatic switching between fresh air and recirculation modes. The instrument cluster air quality display may show '--' or a fixed value, but the fault does not affect the vehicle powertrain or basic air conditioning cooling and heating functions.B173CDTC B173C indicates the Supplemental Restraint System (SRS) detects the Right Second Row Side Airbag squib circuit resistance exceeds the calibrated threshold (typically >4.5Ω). This fault is an active diagnostic result of the SRS system, indicating a high-resistance condition in the circuit between the Airbag Control Unit (ACU) and the airbag module. Causes for excessive resistance include increased contact resistance, a partially broken wiring harness, terminal oxidation, or an aging squib wire inside the airbag module. This fault causes the system to mark the airbag circuit as 'unreliable', meaning the airbag may fail to deploy during a collision. The fault typically illuminates the instrument cluster airbag warning light (SRS light) continuously, and some models also sound a warning buzzer.
Common problems reported for Atto 8 →Atto 8 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.