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C059500

DTC C059500 indicates an abnormal internal power drive circuit or supply voltage in the IPB (Integrated Power Brake) system — Atto 3

Braking System

DTC C059500 indicates an abnormal internal power drive circuit or supply voltage in the IPB (Integrated Power Brake) system.

This fault involves abnormal electrical performance of the power management unit (PMU) or DC-DC conversion circuit inside the IPB module, or the external power supply wiring.

The IPB controller triggers this DTC when it detects the internal drive voltage exceeds normal thresholds (typically below 9V or above 16V), excessive power supply ripple, or an abnormal internal drive MOSFET/IGBT circuit.

This fault can cause vacuum boost simulation failure, a hard brake pedal, energy recovery interruption, and restricted ESC/ABS functions.

In severe cases, the vehicle enters limp mode or fails to power up the high-voltage system.

This constitutes a critical driving safety fault.

4
Cases Logged
Real-World Cases
BYD DTC AI Analysis

Blown fuse causes IPB power supply abnormality in Song PLUS DM-i

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Vehicle failed to engage high voltage. Instrument panel displayed "Brake System Fault" and "Check Powertrain". VDS read current fault code C059500. Checked the engine compartment fuse box and found the IPB 30A fuse blown; the replacement blew immediately. Measured resistance from the IPB supply terminal to ground and found an intermittent short (fluctuating around 50Ω). Diagnosed IPB internal power module breakdown. Replaced the IPB assembly and fuse, performed brake bleeding and calibration. Fault cleared.
BYD DTC AI Analysis

Loose wiring harness connector causing intermittent fault in Seal EV

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Owner reported intermittent "Braking System Fault" warnings on the instrument cluster while driving. Warnings cleared after restarting and occurred 2-3 times daily. Shop inspection found stored DTC C059500. The IPB wiring harness 32-pin female connector had pin retraction on power pins 12 and 13; male terminals showed minor oxidation. Water ingress into the front compartment had deteriorated the connector seal. Technicians extracted and reseated the pins using a dedicated extraction tool, cleaned the connector, reapplied waterproof conductive grease, and secured the harness retaining clips. One-week follow-up confirmed the fault has not recurred.
BYD DTC AI Analysis

Han EV auxiliary battery drain caused C059500 and linked faults

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After 5 days parked, vehicle failed to start. Jump-started; multiple dash warnings appeared. Scanned codes: C059500 (brake booster power supply abnormal), U0146 (communication fault with IPB). 12V battery measured 8.2V, 23% health. Replaced battery, cleared codes; C059500 did not return. Root cause: Severe discharge dropped IPB supply voltage below 9V threshold, triggering power anomaly protection. Check parasitic draw or replace battery.
BYD DTC AI Analysis

BYD Qin PLUS DM-i IPB internal driver board damaged

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The brake pedal suddenly went stiff, requiring heavy effort to depress. The ABS and ESC warning lights stayed on. The scan tool showed code C059500 (current and cannot be cleared). Checked supply voltage at 12.8V – normal. Ground – normal. CAN bus voltage around 2.5V – normal. Disassembled the IPB assembly and inspected the internal circuitry. Found the output capacitor on the DC-DC chip (typically TPS or Infineon series) on the power driver board was bulging, with unstable output voltage fluctuating between 5-8V. Replaced the IPB assembly. Fault resolved, brake assist returned to normal.
Other Atto 3 Fault Codes
P0A0DBattery Energy Control Module Requested MIL IlluminationP0AA6Hybrid Battery Voltage System Isolation FaultP1A00Drive Motor "A" Performance — BYD proprietaryB1108For 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.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.
Data confidence: Community This information is for reference only. Always consult a qualified technician for diagnosis and repair. Do not attempt high-voltage system repairs yourself.