AU
C059592

The IPB (Intelligent Power Brake) system triggers this DTC when the internal power drive circuit of the Electrical Booster detects an abnormal power supply — Atto 8

Braking System

The IPB (Intelligent Power Brake) system triggers this DTC when the internal power drive circuit of the Electrical Booster detects an abnormal power supply.

The IPB system integrates the conventional vacuum booster, ABS, ESP, and EPB into a single unit, and uses a motor-driven hydraulic system to generate brake assist.

DTC C059592 indicates the control module detects the booster motor supply voltage falls outside the normal threshold (typically 9-16V), or the internal DC-DC conversion circuit, power drive MOSFET, or power management chip operates abnormally.

This fault disables or limits the electric brake assist function and significantly stiffens the brake pedal (requiring over 200N of pedal force).

Simultaneously, the system triggers safety protection mechanisms, restricting ADAS functions such as Autonomous Emergency Braking (AEB) and Adaptive Cruise Control (ACC), severely compromising driving safety.

5
Cases Logged
5
Causes
Likely Causes — Atto 8
  • 1Low-voltage power supply system fault: Increased internal resistance due to battery aging, insufficient alternator charging, or voltage regulator fault causes voltage to drop below 9V during startup or high-current operating conditions.
  • 2Wiring connection fault: Poor contact at the IPB power supply circuit fuse (usually 30A or 40A), loose power connector, oxidized or backed-out terminals, or loose ground points G06/G08 causing excessive circuit resistance.
  • 3IPB internal power module fault: Internal DC-DC converter damaged, assist motor drive circuit shorted/open, PCB power components damaged by overheating.
  • 4Brake booster motor internal fault: Short or open circuit in the motor winding causes abnormal current, triggering power supply protection.
  • 5Environmental factors: Poor heat dissipation at the IPB mounting location triggers thermal protection, or plug seal failure allows water ingress, causing internal circuit corrosion and short circuits.
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, voltage, and pedal position. Check for related fault codes such as C059500 and C058200.
  • 2
    Check the vehicle low-voltage power supply system: measure the battery static voltage (should be ≥12.4V), cranking voltage (should be ≥9.6V), and charging voltage (should be 13.8-14.8V). Check the battery internal resistance and State of Health (SOH).
  • 3
    Check the IPB power supply circuit: Check the IPB power supply fuse (usually F1/30A or F2/40A) and relay in the engine compartment fuse box. Measure the voltage at IPB connector terminals B01-1 (+BAT constant power) and B01-2 (+IG1 ignition power). Check the tightness of ground points G06 and G08 and measure the ground resistance (should be <1Ω).
  • 4
    Dynamic voltage test: Measure voltage fluctuation at the IPB connector during vehicle startup and power assist motor operation. Verify no instantaneous voltage drops or spikes occur.
  • 5
    Check the physical condition of the IPB: verify the IPB mounting bracket is secure, heat dissipation is adequate, the connector shows no signs of water ingress or corrosion, and the sealing ring is intact.
  • 6
    Perform system bleeding: If brake fluid was replaced or brake lines were disconnected, run the IPB electric bleeding procedure to eliminate motor overload caused by trapped air.
  • 7
    Software flashing and calibration: Flash the IPB control program to the latest version. If the fault persists, replace the IPB assembly.
  • 8
    Calibration after replacement: After replacing the IPB, perform yaw rate sensor calibration, brake pedal position sensor zero-point learning, linear valve learning, and the brake line bleeding procedure.
Real-World Cases
BYD DTC AI Analysis

Loose power supply connection caused power assist failure in Seal 06 DM-i

✓
Dashboard showed brake system fault, ESP warning light illuminated, and brake pedal became hard. Scan tool read IPB system DTC C059592 (Electrical booster power supply abnormal). Found loose connection in IPB power supply fuse holder; voltage dropped to 8.2V under high current. Repaired fuse holder terminals and tightened power wiring harness connectors to clear the fault. One week later the fault returned. Further testing found intermittent open circuit in IPB internal power module. Replaced IPB assembly and performed calibration to resolve.
Original source ↗
BYD DTC AI Analysis

Excessive battery voltage drop during cold start triggered Han EV fault

✓
The owner reported occasional heavy brake pedal on cold starts, with the instrument cluster displaying "Check Brake System". The fault cleared after warmup. Retrieved historical DTC C059592. Testing revealed battery degradation (internal resistance 18mΩ, state of health 62%). Voltage dropped to 8.5V at startup, causing insufficient power to the IPB assist motor and triggering protection. Replaced the battery and tightened the IPB ground lead. Monitored cold starts for one week with no recurrence.
Original source ↗
BYD DTC AI Analysis

Song PLUS DM-i IPB poor heat dissipation causing intermittent fault

✓
While driving, the instrument cluster suddenly displayed a brake system fault. The ABS and ESP warning lights illuminated and brake pedal travel increased. Scanning revealed codes C059592 and C058200 (abnormal motor circuit signal). The fault occurred intermittently, returning after 50-100 km once cleared. Inspection showed the IPB mounted close to the turbocharger; a missing heat shield caused internal overheating of the control unit, activating thermal protection in the power module. Reinstalled the heat shield, cleaned the IPB connector and applied conductive grease. The fault has not recurred.
Original source ↗
BYD DTC AI Analysis

Qin PLUS DM-i brake booster motor internal short circuit

✓
The brake pedal gradually hardened until almost no assist remained, with the instrument panel showing continuous warnings. Retrieved DTC C059592. Measured IPB supply voltage at 12.8V (normal), but the scan tool showed abnormal booster motor current: peak exceeded 30A then suddenly dropped to zero. Disassembled the IPB and found partial short circuit in the brake booster motor windings, triggering internal drive circuit overload protection. Replaced the IPB integrated brake unit assembly, calibrated the yaw rate sensor, bled the brakes, and cleared the fault.
Original source ↗
BYD DTC AI Analysis

Water ingress corroded the Dolphin's IPB connector, causing abnormal power supply.

✓
Brake system fault after vehicle drove through water; dashboard displayed "Service Brake System". Found IPB connector seal damaged with water inside and green corrosion on pins. Cleaned and dried connector; fault temporarily cleared but returned after two days. Measured power pin contact resistance at 3.2Ω (normal <0.5Ω), causing voltage drop to booster motor under load. Replaced IPB wiring harness connector, cleaned ground point, and replaced IPB assembly (internal circuit corrosion). Fault fully resolved.
Original source ↗
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.