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C053F00

DTC C053F00 indicates an electrical circuit fault in Primary Pressure Sensor 1 within the IPB (Intelligent Integrated Braking System, One-Box brake-by-wire unit) — Seal 6 EV

Braking System

DTC C053F00 indicates an electrical circuit fault in Primary Pressure Sensor 1 within the IPB (Intelligent Integrated Braking System, One-Box brake-by-wire unit).

Specifically, the signal circuit, 5V supply circuit, or ground circuit has a short to ground, short to power, or open circuit.

This sensor is a core input component of the brake-by-wire system.

It monitors brake master cylinder hydraulic pressure or pedal simulator pressure in real time, providing critical data for brake assist, energy recovery, ESC vehicle stability, and AEB automatic emergency braking.

When this fault occurs, the IPB immediately enters limp-home mode, potentially causing a loss of brake assist, a hard brake pedal, and complete deactivation of ABS and ESC functions.

This severe fault compromises driving safety.

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Cases Logged
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Causes
Likely Causes — Seal 6 EV
  • 1IPB wiring harness connector (32-pin or 48-pin plug) seal failure. Water ingress after wading or high-pressure washing causes pin corrosion and oxidation, resulting in intermittent short or open circuits.
  • 2Pressure sensor 1 internal circuit damage (sensor typically integrates into the IPB assembly; do not replace separately), possibly due to overvoltage, overheating, or component aging.
  • 3Chassis bottoming out or a detached wiring harness retaining clip causes wiring harness chafing, resulting in a signal wire short to body ground or the 12V power supply wire.
  • 4Internal signal processing circuit fault in the IPB controller (ECU hardware fault), preventing correct acquisition of sensor analog signals.
  • 5Overdue brake fluid replacement causes excessive water content. The fluid leaks at the sensor mounting seat into the electrical connector, causing a short circuit and corrosion.
What To Do
  • 1
    Safety preparation: Wear insulated gloves and safety goggles. Disconnect the low-voltage battery negative terminal, remove the Manual Service Disconnect (MSD), and wait at least 5 minutes for the high-voltage capacitors to discharge.
  • 2
    Visual inspection: Inspect the exterior of the IPB assembly at the front compartment firewall. Check the wiring harness connector for looseness, backed-out pins, water stains, white corrosion, or signs of brake fluid leakage. Verify sealing ring integrity.
  • 3
    Power supply and ground verification: Connect the diagnostic tool, turn the ignition ON, enter the IPB system, read the data stream, and check the Pressure Sensor 1 voltage. Use a multimeter to measure the sensor power supply pin (typically a 5V reference voltage, range 4.8-5.2V) and ground resistance (must be less than 1Ω).
  • 4
    Circuit continuity and insulation test: Disconnect the IPB connector. Measure the continuity resistance of the pressure sensor 1 signal wire from the IPB connector terminal to the internal circuit (or sensor terminal) (must be less than 1Ω). Measure the insulation resistance of the signal wire to ground (must be greater than 10MΩ) and to the 12V power supply (must be greater than 10MΩ).
  • 5
    Sensor signal simulation: Use an oscilloscope or diagnostic tool to perform an active test and observe if the Pressure Sensor 1 signal changes linearly with brake pedal application. If the signal remains at 0V, 5V, or out of range (e.g., 65535 kPa), this indicates an internal fault in the sensor or ECU.
  • 6
    Repair or replace: If a wiring harness fault exists, repair it and apply waterproof insulation; if an IPB internal sensor or ECU fault is confirmed, replace the IPB assembly (retain the original brake hose and bracket). After replacement, use VDS2000/VDS3000 to perform the IPB coding configuration.
  • 7
    System calibration and bleeding: Perform the brake system bleeding procedure (use the diagnostic tool to drive the motor pump for bleeding). Perform pressure sensor zero-point calibration and pedal travel calibration. Verify no residual air.
  • 8
    Function check: Clear the fault code, perform a road test, and verify normal operation of the ABS, ESC, energy recovery, and automatic emergency braking functions. Confirm C053F00 does not return.
Real-World Cases
BYD DTC AI Analysis

Song PLUS DM-i: Water ingress corroded IPB connector after wading

✓
After driving through water, the dashboard displayed a brake system fault. Read fault code C053F00. Inspection found water ingress and green corrosion inside the IPB harness connector (located near the left front chassis rail). Resistance between the power and signal pins of pressure sensor 1 measured only 200Ω (abnormal). Cleaned the connector thoroughly with electronic cleaner, dried it, applied conductive grease, and replaced the waterproof seal. Fault resolved. Check the front compartment seal and waterproofing at the IPB mounting location.
BYD DTC AI Analysis

Seal EV: Replaced IPB assembly to resolve internal sensor fault

✓
While driving, the ABS/ESC warning light suddenly illuminated, the brake pedal went hard, and DTC C053F00 set. Checked wiring harness, power supply (5V normal), and ground—all normal. No shorts or opens in the signal line. Oscilloscope showed sensor output stuck at 4.9V without changing with pedal movement (normal: 0.5–4.5V linear). Diagnosed as IPB internal pressure sensor 1 failure. Replaced the IPB assembly (part number 1314600-XX), performed coding and brake bleed calibration. Fault resolved.
BYD DTC AI Analysis

Yuan Plus chassis wiring harness wear caused intermittent short circuit

✓
Owner reported intermittent brake system warnings, easily triggered on rough roads. Scan tool retrieved stored DTC C053F00. Raised the vehicle and found the IPB-to-body harness transition had detached from its retaining clip at the firewall penetration. The harness had chafed against the steering rack boot, damaging the signal wire insulation and causing intermittent shorts to ground. Repaired the damaged harness with double-layer heat-shrink tubing, resecured the routing, and added corrugated tubing protection. The fault has not reoccurred.
BYD DTC AI Analysis

Qin PLUS DM-i software false positive fixed by reflash

✓
New vehicle set C053F00 during PDI. Checked wiring harness, sensor power supply and signal — all normal. IPB hardware was early revision. Suspected early software version had a bug in the pressure sensor signal filtering algorithm, causing intermittent false positives. Resolution: Upgraded IPB module software via VDS (V1.02 to V1.05). Cleared fault codes after upgrade. Road tested multiple times without recurrence. No hardware replacement required.
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.