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) — Seal 6 EV

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 Seal 6 EV indicates an abnormal coasting regenerative torque signal between the Vehicle Control Unit and the Intelligent Integrated Braking System. Severity is medium, as it can reduce or disable energy recovery and may appear with brake system faults. Common causes include poor CAN line contact, abnormal terminating resistance, or brake hydraulic issues affecting feedback. The recommended fix is to visit an authorised dealer for diagnosis and repair. Typical repair cost data is available.
4
Cases Logged
5
Causes
Likely Causes — Seal 6 EV
  • 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 hydraulic line) or contaminated and degraded brake fluid causes abnormal hydraulic feedback, triggering a VCU calculation error.
  • 3Internal CAN receive circuit fault in the IPB Intelligent Integrated Brake Control Module, outdated software version, or missing calibration data.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) causing water ingress, damage, or pin back-out at the wiring harness connector.
What To Do
  • 1
    Use the BYD VDS diagnostic tool to read all fault codes and record whether related fault codes, such as C055E00 (hydraulic circuit leak) and C007200 (pedal signal implausible), are present.
  • 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. Inspect the connectors in areas prone to water ingress, such as the front passenger A-pillar and firewall.
  • 3
    Perform the standard brake system bleeding procedure and check the brake fluid flow at each wheel cylinder, specifically inspecting the right front brake caliper hose for foreign object blockages or deformation.
  • 4
    Check brake fluid quality (color, water content). If necessary, thoroughly flush the 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 coasting, verify the VCU regenerative torque signal value changes smoothly and the IPB receive frame counter shows no jumps.
  • 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

✓
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.

✓
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

✓
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.

✓
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 Seal 6 EV Fault Codes
B1108For 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.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.B1737DTC B1737 indicates the Supplemental Restraint System (SRS) detected abnormal continuity between the right middle-row side airbag squib circuit (typically the second-row right seat side airbag or right curtain airbag) and the vehicle power supply (B+, battery positive). The SRS ECU monitors the airbag inflator resistance via an internal current source (normal resistance: 2.0–3.0 Ω). If the ECU detects the voltage across the inflator circuit remaining close to battery voltage (>5 V and approaching 12 V) instead of the expected low potential or floating state, it identifies a short to power. This fault prevents the airbag from deploying normally during a collision because the short circuit bypasses the firing current. In extreme cases, abnormal current can cause unintended deployment, posing a severe safety hazard.B173BDTC B173B indicates an abnormal electric A/C compressor speed feedback signal or a communication fault between the compressor controller and the motor. In BYD new energy models (e.g., Tang, Song, Qin, and Yuan series), this DTC belongs to the HVAC subsystem within the Body Control system and specifically involves the electric compressor closed-loop control circuit. The ECU sets this DTC when the compressor controller (IPM) fails to receive a valid pulse signal from the Hall speed sensor for more than 3 continuous seconds, or when the deviation between the detected actual speed and the target commanded speed exceeds the calibrated threshold (typically >500 rpm). This fault forces the A/C system into fail-safe mode and stops compressor operation. Symptoms include a complete lack of cooling, intermittent cooling, or a sharp decrease in cooling performance. The instrument cluster A/C warning lamp may also illuminate. Prolonged operation with this fault can degrade high-voltage system insulation or cause controller overcurrent damage.
Common problems reported for Seal 6 EV →Seal 6 EV 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.