AU
C050800

DTC C050800 indicates an abnormal short circuit between the right front wheel speed sensor power supply circuit (typically a 12V or 5V reference voltage) and body ground (GND) — Qin Plus

Braking System

DTC C050800 indicates an abnormal short circuit between the right front wheel speed sensor power supply circuit (typically a 12V or 5V reference voltage) and body ground (GND).

In the BYD IPB (Integrated Power Brake) architecture, the active wheel speed sensors (Hall-effect or magnetoelectric) require a stable operating voltage from the ECU.

When the power supply line shorts to ground, the IPB module detects an abnormal current increase or a voltage drop to near 0V and triggers the fault protection mechanism.

This fault causes the loss of the right front wheel speed signal, disabling or degrading functions such as the Anti-lock Braking System (ABS), Electronic Stability Control (ESC), Traction Control System (TCS), and Automatic Emergency Braking (AEB).

This hard fault severely impacts driving safety.

5
Cases Logged
5
Causes
Likely Causes — Qin Plus
  • 1Damaged right front wheel speed sensor wiring harness insulation: Long-term friction and vibration at the steering knuckle, suspension control arm, or body pass-through points wears through the outer sheath, causing the internal power wire to contact the metal body and create a short to ground.
  • 2Internal short circuit in the sensor body: Hall element or internal circuit board fault shorts the power supply pin to the housing, commonly caused by sensor aging, overheating, or water ingress corrosion.
  • 3Connector water ingress or corrosion: Poor sealing of the right front wheel speed sensor connector (located in the fender liner or engine compartment) allows water to accumulate inside after car washing or driving through water, causing a short circuit between the power and ground terminals.
  • 4IPB control unit internal drive circuit fault: The voltage regulator circuit or MOSFET inside the IPB module supplying power to the wheel speed sensors failed, causing a short to ground at the output terminal. Multiple wheel speed sensors may simultaneously report power supply short circuit faults.
  • 5Modification or accident repair damage: During mud flap installation, brake system modification, or accident repairs, retaining clips crush the wiring harness, screws pierce the harness, or incorrect routing causes contact with sharp edges.
What To Do
  • 1
    Safety check and pre-diagnosis: Connect the VDS diagnostic tool to confirm the DTC status is Active. Read the right front wheel speed sensor data stream to confirm no signal output. Check if the IPB power supply fuse is blown (a blown fuse indicates a severe short circuit). Disconnect the IPB and right front wheel speed sensor connectors. Measure the resistance to ground at the sensor-side power pin. A reading below 1Ω confirms a short to ground.
  • 2
    Wiring harness visual inspection: Raise the vehicle, remove the right front wheel and fender liner, and inspect the wiring harness sheath along the entire wheel speed sensor harness routing (from the wheel hub bearing → steering knuckle → fender liner → engine compartment) for wear, cuts, or burn marks. Focus on the interference points between the harness and the steering knuckle, brake hose, and suspension spring, and inspect the rubber grommet at the body pass-through for aging or detachment.
  • 3
    Sectional isolation measurement: Disconnect the wiring harness at the sensor connector. Measure the resistance between the sensor body power terminal and the housing (normal resistance is infinite; if continuity exists, replace the sensor). Measure the resistance to ground of the harness-side power wire. If the harness side has a short circuit, use the bisection method to strip the harness at the midpoint of the routing for inspection. Gradually narrow down the fault area to the exact point of damage.
  • 4
    In-depth connector inspection: Inspect the sensor connector terminals for push-out, deformation, or green corrosion. Measure the insulation resistance between the female connector power pin and the adjacent ground pin. The resistance must be greater than 10MΩ. If water ingress is present, dry the connector with compressed air and clean it with electronic contact cleaner. Replace the connector assembly and improve the sealing if necessary.
  • 5
    IPB module verification: If the wiring harness and sensor are normal, measure the resistance to ground at the power supply output terminal on the IPB harness side. If continuity exists, disconnect the IPB connector and measure the resistance to ground at the corresponding module pin. After confirming an IPB internal short circuit, replace the IPB assembly (perform bleeding and calibration procedures).
  • 6
    Repair and Verification: Repair the wiring harness (solder + heat-shrink tubing + corrugated conduit protection) or replace the sensor/IPB. Restore all connections and clear the fault code. Perform a key cycle test to confirm the fault code does not return. Road test the vehicle (accelerate and decelerate between 10-40 km/h) to confirm the right front wheel speed signal synchronizes with the other wheel speeds and the ABS self-check shows no abnormalities.
Real-World Cases
BYD DTC AI Analysis

Song PLUS DM-i right front wheel speed sensor wiring harness chafed through at steering knuckle and shorted

✓
After driving through water, the ABS light illuminated with DTC C050800. Inspection revealed the right front wheel speed sensor harness had chafed where it passes through the steering knuckle retaining clip. Prolonged steering movement wore through the insulation, exposing copper wires that contacted the steering knuckle metal and shorted to ground. Repaired the damaged harness (3 wires, including the power wire shorted to ground), rewrapped and rerouted the wiring, and fitted a rubber grommet to prevent contact with sharp edges. Replaced the damaged waterproof connector. Fault resolved.
BYD DTC AI Analysis

Internal driver circuit failure in the IPB module caused a short circuit in the power supply to multiple wheel speed sensors.

✓
Post-accident repair. DTC C050800 set after right-front impact. Harness visually intact; sensor readings normal. Disconnected IPB connector and measured 0.2Ω to ground on the supply pin at the harness side. Replaced right-front wheel speed sensor; fault persisted. Found the LDO regulator supplying the right-front sensor shorted inside the IPB. Replaced IPB assembly, bled IPB and calibrated sensors; fault resolved.
BYD DTC AI Analysis

Internal short circuit in the sensor body caused intermittent DTC C050800

✓
Owner reported intermittent ABS warning light on, particularly frequent during wet weather. Scanner showed DTC C050800 as an intermittent fault. Harness insulation tested good, but wiggling the sensor harness reproduced the fault. Removed the sensor and measured resistance between the internal power terminal and housing: erratic, fluctuating between infinite and continuity. Internal Hall element encapsulation seal failed, causing internal short in humid conditions. Replaced right front wheel speed sensor. Fault eliminated.
BYD DTC AI Analysis

Modified brake lines pinched wiring harness, causing short circuit

✓
One week after fitting a high-performance braking system, DTC C050800 appeared. Inspection found the modified braided brake line mounting bracket incorrectly positioned, pinching the original wheel speed sensor harness and shorting the power wire to the shield/ground inside the loom. Rerouted the harness, adjusted the brake line mounting points, and repaired the damaged wiring (insulation breached at 3 points). Fault cleared. Retain the original wiring harness clip positions when modifying.
BYD DTC AI Analysis

Connector terminal backed out, causing power pin to contact metal bracket

✓
The ABS warning light suddenly came on after driving over rough road. Inspection found the right front wheel speed sensor connector wasn't fully locked. The internal power terminal (female) had backed out and contacted the metal retaining clip of the connector housing, shorting to ground through the body. Cleaned the connector internals, repaired the terminal retention structure, and ensured the connector clicked fully into place (heard the 'click'). Applied conductive grease to prevent oxidation. Fault 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.