AU
C058F00

DTC C058F00 indicates an abnormal coasting regenerative torque signal status in CAN message 0x410 transmitted from the VCU (Vehicle Control Unit) to the IPB (Intelligent Integrated Braking System) — Atto 8

Braking System

DTC C058F00 indicates an abnormal coasting regenerative torque signal status in CAN message 0x410 transmitted from the VCU (Vehicle Control Unit) to the IPB (Intelligent Integrated Braking System).

In the BYD New Energy architecture, the VCU calculates the target regenerative torque during coasting or braking (typically 0-150 Nm) and transmits it to the IPB via a CAN message.

The IPB uses this signal to coordinate motor and hydraulic braking force distribution for energy recovery.

This fault indicates the IPB received a regenerative torque signal with a data validation error, an update timeout, or an out-of-range value (such as a negative value or sudden change), or communication synchronization failed between the VCU and IPB.

This fault frequently accompanies brake system DTCs such as C055E00 (hydraulic circuit leakage), triggering energy recovery system derating or protective shutdown.

The C058F00 fault code on the Atto 8 indicates a medium-severity problem with the coasting regenerative torque signal sent from the VCU to the braking system. It may be caused by poor CAN wiring contact, abnormal CAN resistance, signal interference, or brake hydraulic issues affecting torque calculation. Regenerative braking may be reduced or disabled. The recommended fix is to visit an authorised dealer for diagnosis and repair. Typical repair cost data is available.
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Cases Logged
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Causes
Likely Causes — Atto 8
  • 1Poor contact in the CAN communication line between VCU and IPB, abnormal terminating resistance (standard: 60Ω), or electromagnetic interference causing signal frame loss.
  • 2Blocked brake caliper hydraulic line (e.g., foreign object in the right front brake caliper line) or contaminated and degraded brake fluid causes abnormal hydraulic feedback, triggering a VCU calculation error.
  • 3Internal CAN receiving circuit fault in the IPB intelligent integrated brake control module, outdated software version, or missing calibration data.
  • 4Vehicle Control Unit (VCU) internal algorithm fault, unstable power supply, or abnormal signals from related sensors (motor speed, brake pedal position).
  • 5Non-professional vehicle modifications (such as painting or installing additional equipment) caused water ingress, damage, or backed-out pins in the wiring harness connector.
What To Do
  • 1
    Use the BYD VDS diagnostic tool to read the complete fault codes. Record any accompanying related fault codes, such as C055E00 (hydraulic circuit leak) and C007200 (pedal signal implausible).
  • 2
    Measure the CAN-H and CAN-L line voltages (standard: CAN-H 2.5-3.5V, CAN-L 1.5-2.5V) and terminal resistance between the VCU and IPB. Check connector conditions in areas prone to water ingress, such as the front passenger A-pillar and firewall.
  • 3
    Perform the standardized brake system bleeding procedure and check the brake fluid flow at each wheel cylinder. Specifically inspect the right front brake caliper hose for foreign object blockages or deformation.
  • 4
    Check brake fluid quality (color, water content). If necessary, thoroughly flush brake lines and replace with DOT4 brake fluid.
  • 5
    Check the VCU and IPB software versions against the BYD technical bulletin. Perform a software update or module reset if necessary.
  • 6
    Enter data stream monitoring mode. While the vehicle is coasting, observe whether the VCU regenerative torque signal value changes smoothly and verify the IPB receive frame counter does not jump.
  • 7
    If the above checks are normal, test the IPB assembly or VCU by substitution. After replacement, bleed the brake system, calibrate the steering angle, and perform energy recovery function learning.
Real-World Cases
BYD DTC AI Analysis

All-new generation Tang DM brake lock-up with regenerative torque signal abnormality

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The vehicle arrived with the instrument cluster showing a brake system fault and the right front wheel binding. Technicians used VDS to read DTCs C055E00 (Hydraulic Circuit Leakage) and C058F00 (Feedback Torque Signal Abnormal). They suspected the IPB assembly and replaced it, but the fault remained. Inspection found foreign matter from spray painting inside the right front brake caliper hose, causing a localized hydraulic blockage. The VCU triggered false codes due to the abnormal hydraulic feedback. Cleaning the foreign matter from the hose and re-bleeding the system cleared the fault completely.
Original source ↗
BYD DTC AI Analysis

Water ingress corroded the VCU-to-IPB communication line, causing intermittent signal interruption.

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Driver reported the ESC warning light occasionally illuminating after driving in rainy conditions, with regenerative braking suddenly cutting out while coasting. The diagnostic tool showed stored fault code C058F00. Inspection found water ingress at the VCU-IPB CAN wiring harness connector beneath the passenger-side A-pillar. Pin surface oxidation increased contact resistance (measured 120Ω, exceeding the 60Ω±5% specification). Technicians cleaned the connector terminals, applied conductive paste, and resealed the connector. No recurrence after one week of continuous monitoring.
BYD DTC AI Analysis

IPB intelligent brake module internal receiver chip cold solder joint fault

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Cold starts triggered frequent brake system fault warnings on the instrument cluster; the warning light went out after the vehicle warmed up. VDS detected DTC C058F00 as currently present but clearable. CAN data monitoring revealed periodic counter skips in the 0x410 message frames received at the IPB (1 frame lost every 10), while the VCU transmitted normally. Disassembling the IPB control unit revealed dry solder joints on the CAN transceiver chip pins. Resoldering the connections fixed the fault and avoided replacing the expensive IPB assembly.
BYD DTC AI Analysis

Severely contaminated brake fluid caused distorted feedback from the hydraulic pressure sensor.

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After maintenance, the brake pedal felt spongy and regenerative braking failed. Retrieved DTC C058F00. Found the customer had added non-compliant brake fluid at an external workshop, causing severe emulsification and blackening. The IPB's internal hydraulic pressure sensor drifted due to the changed fluid dielectric constant, so the VCU misinterpreted this as a regenerative torque calculation basis error. Flushed the entire brake system (including the ABS valve body internals), refilled with genuine DOT4 brake fluid, and bled. System returned to normal.
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.