AU
C007200

C007200 is an advanced diagnostic trouble code in the BYD Integrated Power Brake (IPB) system — Seal 6 EV

Braking System

C007200 is an advanced diagnostic trouble code in the BYD Integrated Power Brake (IPB) system.

It indicates an abnormal thermal condition or pressure-temperature correlation in hydraulic brake circuit A (typically the front brake circuit).

The system triggers this code based on a combined assessment of real-time master cylinder pressure sensor data, the hydraulic valve body temperature prediction model, and the braking frequency algorithm.

The system records this fault when brake fluid temperature exceeds the preset threshold (typically caused by frequent braking, throttling heat generation from internal hydraulic leakage, or high ambient temperatures), or when the pressure sensor signal logically mismatches the temperature model.

This fault may degrade ESP/ABS functions, cause abnormal brake pedal feel (soft or hard), and restrict regenerative braking.

Severe cases trigger overheat protection and cut off power output.

The C007200 fault code on the Seal 6 EV indicates an abnormal temperature or pressure-temperature mismatch in hydraulic brake circuit A within the Integrated Power Brake system. Severity is medium, as it may affect ABS/ESP, pedal feel, and regenerative braking. Common causes include brake fluid heat build-up from frequent heavy braking or internal leakage in the IPB valve body. Visit an authorised dealer for diagnosis and repair. Typical repair cost data is available from 3 recorded cases.
3
Cases Logged
5
Causes
Likely Causes — Seal 6 EV
  • 1High-intensity continuous braking conditions cause brake fluid heat build-up (e.g., long downhill sections, aggressive driving, or frequent hard acceleration/deceleration).
  • 2Aging or wear of the IPB hydraulic valve body internal seal causes internal hydraulic leakage (not externally visible), resulting in a temperature rise due to throttling.
  • 3Master cylinder pressure sensor signal drift, zero-point deviation, or internal sensor fault, transmitting incorrect pressure-temperature correlation data to the ECU.
  • 4Poor contact, pin oxidation, or waterproof seal failure at the IPB control unit wiring harness connector (located near the engine compartment firewall), causing signal interference.
  • 5Abnormal wheel speed sensor signal (contamination or damage) causes frequent ESP system actuation to regulate hydraulic pressure, resulting in excess heat build-up.
What To Do
  • 1
    Use VDS or a dedicated diagnostic tool to read the DTC freeze frame data. Verify the vehicle speed, brake pressure, calculated temperature, pedal travel, and driving conditions (e.g., whether energy recovery mode was active) at the time of the trigger.
  • 2
    Visually inspect the brake fluid level (must be between MAX and MIN), the brake fluid color (for deterioration or blackening), and the external brake lines, hoses, and wheel cylinders for physical leaks.
  • 3
    Check the IPB control unit connector (located on the left or right side of the engine compartment firewall, with a waterproof sealing cover) for proper locking, waterproof sealing ring integrity, and oxidized, backed-out, or corroded pins.
  • 4
    Perform the 'Brake Hydraulic System Bleeding' procedure (requires a diagnostic tool to activate the IPB internal bleed pump) and the 'Master Cylinder Pressure Sensor Zero Point Calibration' procedure to clear false warnings caused by sensor drift.
  • 5
    Check the four wheel speed sensor signal waveforms (read the live data stream using an oscilloscope or diagnostic tool). Clean the sensor probes and tone rings to rule out false ESP activation caused by erratic signals.
  • 6
    If the fault is intermittent, perform a wiring harness wiggle test and an IPB control unit heating/cooling test to locate poor connections or internal solder joint faults.
  • 7
    If the above steps fail, measure the IPB hydraulic valve body solenoid resistance (standard value is typically 2-5Ω; refer to the repair manual for exact specifications) and insulation. If necessary, replace the IPB integrated brake assembly and update the control software to the latest version.
Real-World Cases
BYD DTC AI Analysis

Song PLUS DM-i: Software false positive triggers multiple simultaneous DTCs (C007200+C055E00)

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The dashboard simultaneously illuminated the ABS, ESP and brake system warning lights, displaying "Check brake system". The scan tool retrieved DTCs C007200 (Brake temperature too high) and C055E00 (Brake hydraulic circuit A leak) among others. Brake fluid level was normal with no visible external leaks, ruling out physical leakage. Performed "Brake hydraulic system bleed" and "Pressure sensor zero calibration" using the dealership diagnostic tool, then reflashed the ESP control unit software. Fault eliminated. Root cause: IPB system pressure sensor zero drift or software logic miscalculation. Resolved without replacing any hardware.
Original source ↗
BYD DTC AI Analysis

BYD Han DM: Internal Leak in Brake Hydraulic Circuit from Aged Seal

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While driving, the dashboard suddenly displayed 'Brake System Fault' and ABS/ESP functions failed. DTC C055E00 (Brake Hydraulic Circuit A Leak) stored—same hydraulic circuit monitoring fault category as C007200. Lifted the vehicle and inspected the brake calipers and external lines at all four wheels; found no leaks. Removed the ABS/IPB pump and found the internal valve seals had hardened with age, causing internal brake fluid leakage (not external) within the valve body, abnormal hydraulic circulation, and localized overheating. Replaced the ABS/ESP pump assembly (using improved high-temperature seal components), performed brake bleeding and sensor calibration. Fault resolved.
BYD DTC AI Analysis

Contaminated wheel speed sensor on Tang DM triggered false ESP activation, indirectly causing hydraulic overheating.

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While driving at highway speeds, the ESP system triggered erroneously, causing sudden automatic braking and brake pedal shudder. The instrument cluster then displayed a brake system fault. The scan tool showed C0035 (right front wheel speed sensor signal fault), hydraulic circuit pressure anomalies, and C0072-series temperature monitoring faults. Inspection found the right front wheel speed sensor probe covered in iron debris and mud, causing signal fluctuation. This abnormal signal caused the ESP to falsely detect wheel slip, repeatedly adjusting hydraulic circuit pressure, which indirectly overheated the hydraulic valve body and triggered C007200-type temperature monitoring faults. After cleaning the wheel speed sensor probe and tone ring, resetting the IPB system and calibrating the sensors cleared the fault.
Original source ↗
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.