AU
C051500

DTC C051500 indicates the IPB (Intelligent Integrated Braking System) detected a short circuit to battery positive (B+) in the right rear wheel speed sensor power supply circuit — Atto 8

Braking System

DTC C051500 indicates the IPB (Intelligent Integrated Braking System) detected a short circuit to battery positive (B+) in the right rear wheel speed sensor power supply circuit.

This fault occurs when abnormal electrical continuity develops between the sensor power line (typically a 12V supply) and the vehicle constant power supply or the IPB internal power output stage, causing an abnormal voltage increase or current overload.

The IPB control unit monitors the supply circuit voltage and current characteristics.

Upon detecting a short circuit, it triggers a protection mechanism and cuts power to the circuit to prevent hardware damage.

This fault causes the loss of the right rear wheel speed signal, disabling or degrading ABS, ESP, TCS, EPB, and Automatic Emergency Braking (AEB) functions, which severely compromises driving safety.

The '00' suffix in the DTC typically indicates an active, hard fault (non-intermittent).

The C051500 fault code on the Atto 8 indicates a high-severity short to battery positive in the right rear wheel speed sensor power supply circuit. This can cut the sensor signal and affect ABS, ESP, traction control, EPB, and AEB. Common causes include damaged harness insulation from chafing or water/corrosion inside the sensor connector. Visit an authorised dealer for diagnosis and repair. Typical repair cost data is available from recorded cases.
5
Cases Logged
5
Causes
Likely Causes — Atto 8
  • 1Damaged right rear wheel speed sensor harness insulation: Long-term vibration and chafing damage the harness at the rubber grommet where it passes through the body floor or suspension control arm. The power supply wire contacts an adjacent constant power circuit (e.g., tail light power, fuel pump power), creating a short circuit.
  • 2Sensor connector water ingress and corrosion: Vehicle wading, direct high-pressure water jets, or poor sealing causes an internal short circuit, connecting the power supply terminal to an adjacent high-potential terminal or the metal housing.
  • 3Wheel speed sensor internal circuit breakdown: Damage to the sensor's internal voltage regulator circuit or Hall element causes a short circuit between the power input terminal and the signal output terminal or housing, creating a reverse short circuit to the power supply circuit.
  • 4IPB control unit internal power module fault: Output stage breakdown of the wheel speed sensor power supply chip (LDO or DC-DC) inside the IPB causes continuous high voltage output or an internal short circuit. Similar faults in other wheel speed sensors controlled by the same IPB typically accompany this condition.
  • 5Wiring harness damage caused by improper modification or accident repair: Improperly tapping wires for power when installing aftermarket equipment such as dash cams or parking sensors, or improperly wrapping the wiring harness during rear-end accident repairs, resulting in a crushed or incorrectly connected power supply wire.
What To Do
  • 1
    Safety preparation and fault confirmation: Use VDS2000 or Launch X431 to read all fault codes. Verify if C051500 is the only code present or if other wheel speed sensor faults, such as C051400 (short to ground), accompany it. Record freeze frame data (vehicle speed, temperature, and voltage at the time of occurrence). Check the IPB software version and confirm there are no related Technical Service Bulletins (TSB).
  • 2
    Visual and connector inspection: Raise the vehicle and remove the right rear wheel. Inspect the wheel speed sensor connector (usually located near the steering knuckle or brake caliper) for water ingress, corrosion, looseness, or deformed pins. Follow the wiring route and inspect the wiring harness sheath for damage, focusing on the bent sections passing through the floor pan and suspension control arm.
  • 3
    Power supply voltage and resistance measurement: Turn off the ignition, disconnect the right rear wheel speed sensor connector, and measure the resistance to ground at the power supply pin on the connector side (usually pin 1 or 2; refer to the wiring diagram). Normal resistance exceeds 10MΩ. If the resistance is too low, the circuit shorts to power. Turn on the ignition and measure the voltage at this pin. Normal voltage is 12V ± 0.5V. If the measured voltage equals battery voltage (above 12.6V) and shows direct continuity to the battery positive terminal, confirm a short circuit.
  • 4
    Wiring insulation and continuity test: Disconnect the right trunk wiring harness connector (usually located near the right rear fender liner) to divide the circuit into the 'sensor-to-body transition section' and the 'body-to-IPB section'. Use a megohmmeter to measure the insulation resistance of the power wire to the body and to other power wires to isolate the faulty section. Check the IPB control unit connector (located near the engine compartment firewall) for water ingress or corrosion.
  • 5
    Component replacement verification: If circuit insulation is normal, replace the right rear wheel speed sensor (typical part number 3630200-00; verify model compatibility) and test. If the fault persists after sensor replacement and wiring harness verification, the IPB control unit internal power supply module is damaged. Replace the IPB assembly (requires bleeding, calibration, and coding).
  • 6
    Repair verification and functional test: After repairing or replacing the faulty component, clear the fault code and perform a road test (vehicle speed must exceed 40 km/h to activate the wheel speed signal self-check). Use a diagnostic tool to read the wheel speed sensor live data stream. Confirm the right rear wheel speed matches the other wheel speeds and does not fluctuate. Verify the ABS, ESP, and EPB functions operate normally and confirm the warning light is off.
Real-World Cases
BYD DTC AI Analysis

Song PLUS DM-i: Right rear wheel speed sensor power supply short circuit after water ingress

✓
2022 Song PLUS DM-i. ABS and ESP lights stayed on after driving through water. Read DTC C051500. Inspection found obvious water stains and verdigris inside the right rear wheel speed sensor connector; the power supply pin was conducting to the connector housing. Water had seeped through the connector seal during wading, causing the power terminal to short to ground (body)—misdiagnosed as a short to power (or actually shorted to the internal power wire). Cleaned the connector pins, applied conductive grease, replaced the sensor (possible internal damage), and resealed the waterproofing. Fault resolved.
BYD DTC AI Analysis

Worn wiring harness sheath caused intermittent short circuit

✓
2021 Song Pro DM. ESP warning light occasionally illuminates on rough roads; intermittent DTC C051500. On the lift, found the right rear wheel speed sensor harness worn at the rubber grommet where it passes through the suspension arm. Internal insulation had worn through, allowing the power wire to contact an adjacent constant-power reverse light wire. Static measurements normal, but resistance varied when shaking the harness. Repair: Repaired the damaged harness, separated the routing to avoid interference, and added an abrasion-resistant sleeve. Fault has not reoccurred.
BYD DTC AI Analysis

Internal fault in the IPB control unit caused abnormal power supply to multiple sensors.

✓
2023 Seal. DTCs C051500 and C051100 appeared after rear-end collision repairs (left rear wheel speed sensor supply short circuit). Wiring measured normal on both sides, but supply voltage read 14.5V (battery voltage), suggesting IPB internal voltage regulator damage. Traced to a flat 12V battery during the accident; jump starter connected with reversed polarity, causing surge damage to the IPB power module. Replaced the IPB integrated brake assembly, performed hydraulic bleeding, longitudinal sensor calibration, and wheel speed sensor signal learning. Fault resolved.
BYD DTC AI Analysis

Aftermarket reversing sensors incorrectly connected, causing short circuit

✓
2022 Song MAX. Owner installed a reversing camera at a non-authorized shop; DTC C051500 appeared the next day. Inspection found the installer cut into the right rear sill harness to draw power and mistakenly bridged the reverse light supply to the wheel speed sensor power feed, causing high current to enter the sensor circuit. Removed the non-compliant wiring, repaired the damaged factory harness (replaced the entire section to eliminate risks), and restored the original circuits. Explained the risks of unauthorized modifications to the owner.
BYD DTC AI Analysis

Sensor internal short triggered IPB protection

✓
2020 Han EV. C051500 triggered suddenly at 60,000 km. Found 0.5Ω short between the sensor connector supply pin and ground. Disconnected the sensor; harness side tested normal with 12V supply and infinite resistance to ground. Disassembled the sensor and found the internal Hall element burnt with supply and ground terminals shorted. Suspected cause: sensor ageing or internal Zener diode breakdown. Replaced the right rear wheel speed sensor (genuine part), cleared the fault codes, and road test returned to normal. Also check tire balance to rule out long-term overheating from abnormal tire vibration causing premature sensor ageing.
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.