AU
C058200

DTC C058200 indicates the supply voltage to the brake booster motor inside the IPB (Intelligent Integrated Braking System / One-box electro-hydraulic brake-by-wire system) falls outside the normal operating threshold set by the ECU (typically 9-16V DC) — Atto 8

Braking System

DTC C058200 indicates the supply voltage to the brake booster motor inside the IPB (Intelligent Integrated Braking System / One-box electro-hydraulic brake-by-wire system) falls outside the normal operating threshold set by the ECU (typically 9-16V DC).

This brushless DC motor drives the brake master cylinder to generate hydraulic brake assist.

A generator regulator fault, a power supply circuit short, or reversed polarity during jump-starting can cause high voltage (>16V).

A discharged battery, excessive wiring voltage drop, poor ground connection, or internal module DC-DC power supply chip failure can cause low voltage (<9V).

This fault triggers the IPB degraded mode, reducing or completely disabling the brake assist function (hard brake pedal).

The fault may also inhibit ABS/ESC/EBD functions.

In severe cases, the system illuminates the red brake warning lamp, compromising driving safety.

The C058200 fault code on the Atto 8 indicates abnormal supply voltage to the brake booster motor inside the IPB braking system. This is a medium-severity issue that can reduce or disable brake assist, causing a hard brake pedal and possible ABS/ESC/EBD limitations. Common causes include a weak or discharged battery, alternator regulator fault, wiring voltage drop, poor ground, or an internal IPB 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 DC-DC converter, MOSFET drive circuit, or voltage sampling resistor inside the IPB electro-hydraulic module, causing abnormal motor power supply.
  • 2Battery aging, low charge (voltage <11V), or alternator regulator fault causing excessive output voltage (>15.5V)
  • 3Poor contact, loose connections, backed-out terminals, or burnt pins in the IPB power supply circuit or fuses (e.g., F1/16, F2/03, or F4/15, depending on vehicle configuration)
  • 4Vehicle modifications (such as installing high-power electrical accessories or connecting a dashcam to constant power) causing power supply interference or sudden load changes.
  • 5Loose or oxidized front compartment wiring harness to body ground points (G101/G102) increase circuit resistance and cause a voltage drop.
What To Do
  • 1
    Use the VDS2000 or a dedicated BYD diagnostic tool to read the complete fault codes and freeze frame data. Record the specific voltage, vehicle speed, brake pedal travel, and IPB temperature at the time of the fault to determine whether it is continuous or intermittent.
  • 2
    Measure the battery static voltage (normal 12.4-12.8V) and dynamic voltage (idle 13.8-14.4V, acceleration <15.0V). Check the alternator output waveform to rule out a charging system fault.
  • 3
    Check the IPB module fuses (usually located in the left/right front compartment power distribution box) and IPB module body connectors CN1/CN2. Inspect the pins for backing out, corrosion, or water ingress. Measure the voltage drop between the power pins (constant power +B, ignition IG1) and ground (GND). The voltage drop must be <0.1V.
  • 4
    Perform the IPB system function test: execute the bleeding procedure, pedal feel simulation test, and hydraulic circuit test in sequence. Observe the motor operating current (normal: <15A) and voltage fluctuations.
  • 5
    If the wiring and power supply are normal and the fault persists, replace the IPB electro-hydraulic control unit assembly (part number depends on vehicle model, e.g., 6A-3555100-70 for Song PLUS DM-i). After replacement, perform coding configuration, longitudinal sensor calibration, and the ESC bleeding procedure.
Real-World Cases
BYD DTC AI Analysis

Burnt fuse holder on Song PLUS DM-i causing voltage drop

✓
Vehicle presented with intermittent ABS/ESC warning lights and stiff brake pedal while driving. DTCs C058200 (current) and U012187 (history) read. IPB supply voltage measured 8.2 V during fault reproduction; battery voltage remained normal. Front compartment fuse box inspection revealed the IPB 30A fuse (F2/03) holder burnt and pins loose, increasing contact resistance under high current. Replaced the fuse box holder and fuse, polished the IPB connector pins, and retightened the ground cable. Fault resolved.
BYD DTC AI Analysis

Qin PLUS DM-i: Sudden voltage drop during cold start

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Owner reported dashboard warnings during cold starts in northern winter. DTCs C058200 and C003F00 (brake booster motor fault) stored. Measurements checked normal at ambient temperature, but during a -15°C cold start, battery voltage dropped instantly to 9.5V. The IPB internal power supply chip failed to maintain stable output due to poor low-temperature characteristics. Replaced the IPB electro-hydraulic module assembly and recommended the owner install an AGM battery with better low-temperature performance. The fault has not reoccurred.
BYD DTC AI Analysis

Aftermarket dashcam causing power interference on Dolphin

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The owner fitted a dashcam themselves, splicing into the IPB fuse for constant power, causing intermittent C058200 faults while driving. Inspection found the modified wiring had damaged insulation and shorted to the body, creating voltage fluctuations in the IPB supply. Factory wiring was restored, with a separate feed run from the battery positive via the fuse box, returning the IPB system to normal. Do not tap into brake system fuses for modifications.
BYD DTC AI Analysis

Han EV IPB internal MOSFET failure

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While driving, the red brake system warning light suddenly illuminated and the pedal went hard with almost no boost. Scanned DTC C058200 (voltage too high, freeze frame showed 16.8V). Checked alternator and battery voltage – normal. Measured power input at the IPB connector – normal, but the module internally detected an abnormal motor supply. Disassembled the IPB and found the internal motor drive MOSFET had shorted, causing the detection circuit to report voltage out of range. Replaced the IPB assembly and recalibrated. Issue resolved.
BYD DTC AI Analysis

Tang DM-p poor ground connection causing intermittent fault

✓
ABS warning light came on intermittently when driving on rough roads. Read DTC C058200 (low voltage). Found the G101 ground point bolt in the left front engine bay loose and oxidized. The IPB draws high current (20A peak); poor grounding caused circuit voltage drop, and the module detected voltage below threshold. Cleaned the ground point, tightened the bolt to specified torque (10N·m), and applied conductive paste. Fault resolved.
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.