AU
C057F00

This DTC indicates the IPB (Integrated Power Brake) ECU detects abnormal power supply voltage to the brake booster motor — Atto 8

Braking System

This DTC indicates the IPB (Integrated Power Brake) ECU detects abnormal power supply voltage to the brake booster motor.

Conditions include voltage outside the normal range (9-16V), excessive voltage fluctuation, or power supply interruption.

The IPB system uses a motor-driven hydraulic pump to replace the conventional vacuum booster.

The ECU sets this fault when it detects an open circuit, short circuit, undervoltage (typically <9V), or overvoltage (>16V) in the motor power supply circuit.

This fault reduces or disables the brake assist function.

The system may enter Limp Home mode, resulting in a hard brake pedal, increased pedal travel, and an illuminated ABS/ESC warning lamp, severely compromising driving safety.

The C057F00 fault code on the Atto 8 indicates abnormal power supply voltage to the Integrated Power Brake booster motor. This is a medium-severity fault that can reduce brake assist, causing a hard pedal and ABS/ESC warnings. Common causes include a weak or aged 12V battery, charging system fault, or an internal IPB module power circuit fault. Visit an authorised dealer for diagnosis and repair. Typical repair cost data is available.
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Cases Logged
5
Causes
Likely Causes — Atto 8
  • 1Fault in the internal power management circuit or motor drive chip of the IPB electro-hydraulic control module, resulting in abnormal voltage monitoring.
  • 2Severely discharged or aged 12V battery, or generator charging system fault, causing system voltage to drop below 9V.
  • 3Poor contact in the IPB power supply circuit, blown fuse (e.g., F1/23 40A), loose relay connection, or damaged power wiring harness.
  • 4Water ingress, pin corrosion, pin back-out, or seal failure at the IPB wiring harness connector (usually located near the left longitudinal rail in the front compartment) causing a voltage drop.
  • 5Outdated IPB control unit software version or abnormal calibration data causes voltage monitoring threshold drift.
What To Do
  • 1
    Use the VDS2000/VDS3000 diagnostic tool to read the complete fault codes and freeze frame data. Record key parameters at the time of the fault, including vehicle speed, system voltage, and motor current, and determine if the fault is intermittent.
  • 2
    Check the 12V battery status: static voltage must be ≥12.4V and cranking voltage must be ≥9.6V. Verify the alternator output voltage is 13.5-14.5V to rule out a power supply system fault.
  • 3
    Inspect the IPB-related fuse (typically a 40A high-current fuse) and relay in the front compartment fuse box. Measure the voltage drop across the fuse; it must be <0.1V. Inspect the relay contacts for burning or pitting.
  • 4
    Disconnect the IPB wiring harness connector (e.g., B05). Check the pins for push-out, corrosion, or water ingress. Measure the voltage between the power supply terminal (constant +B) and ground; voltage should be approximately 12V. Measure the resistance between the ground terminal (GND) and ground; resistance should be < 1Ω.
  • 5
    Check the IPB ground wire connection point (usually ground point G105) for looseness or oxidation. Clean and tighten the ground bolt. Add a ground wire if necessary.
  • 6
    Use an oscilloscope to monitor the IPB motor supply voltage waveform. Check for voltage drops or spike interference, and inspect the wiring for loose connections.
  • 7
    Flash the IPB control unit software to the latest version (such as an IPB software patch released after 2023), then complete system bleeding and longitudinal acceleration sensor calibration.
  • 8
    If all above checks are normal, replace the IPB electro-hydraulic control module assembly. Complete online coding, bleed the brake lines, and calibrate the ESC system. Road test the vehicle to confirm fault resolution.
Real-World Cases
BYD DTC AI Analysis

Song PLUS DM-i auxiliary battery aging caused IPB voltage fault

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Vehicle parked 3 days. On startup, dashboard displayed "Brake System Fault". Retrieved fault code C057F00. Found 12V battery resting voltage at only 11.2V, dropping to 8.5V on cranking. Replaced battery; fault code cleared but returned after one week. Further inspection found alternator output at only 12.8V (low). Replaced alternator regulator; system voltage restored to 13.8V, fault permanently resolved. Analysis: Battery aging increased internal resistance; voltage drop during cold starting triggered IPB low-voltage protection.
BYD DTC AI Analysis

Water ingress corroded the IPB connector, causing intermittent voltage fault.

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After driving through water, the brake pedal became stiff with DTC C057F00 appearing intermittently. Inspection revealed water inside the IPB wiring harness connector (located beneath the left front side member). The power supply terminal (Pin 1) showed green corrosion with contact resistance of 3.2 Ω (normal <0.5 Ω). Cleared the water from the connector, cleaned the pins with precision electrical contact cleaner, applied conductive grease and replaced the seal. Resolved. Inspect IPB mounting location sealing on vehicles that have waded through water.
BYD DTC AI Analysis

IPB internal motor drive module damaged

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While driving, the ABS/ESC warning light suddenly came on, the brake pedal stiffened, and DTC C057F00 set current and would not clear. IPB supply voltage measured 12.8V (normal) with good ground, but the scan tool showed 0V for the IPB internal motor supply voltage. Disassembled the IPB module and found the internal motor drive MOSFET shorted, preventing the ECU from detecting motor supply voltage. Replaced the IPB electro-hydraulic control module assembly, performed coding and sensor calibration, and the fault resolved.
BYD DTC AI Analysis

Poor contact in the fuse holder caused voltage drop.

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After driving on rough roads, the brake system warning light came on intermittently. DTC C057F00 stored as history code. Inspection found the IPB fuse (40A) socket loose in the front compartment fuse box. Gap between fuse and terminal measured 1.8V voltage drop (normal <0.1V). Adjusted fuse holder tension, tightened terminal tabs using a special tool, applied conductive grease, and reinstalled. Road-tested 20 km with no fault recurrence. Analysis: Vibration caused poor fuse contact; voltage drop under high current triggered the fault.
BYD DTC AI Analysis

Software calibration fault causing false voltage fault

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During new-vehicle PDI, found DTC C057F00. Measured IPB supply voltage at 12.6V — normal. No wiring faults. TSB indicated an IPB software bug in this batch causes false voltage faults under specific conditions (e.g., rapid ignition switch cycling). Updated IPB control unit software via VDS (V1.2 to V1.4), completed longitudinal accelerometer calibration and ESC initialization. Fault code cleared and has not reappeared.
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.