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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) — Qin Plus

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.

The C053F00 fault code on the Qin Plus indicates a high-severity electrical circuit fault in Primary Pressure Sensor 1 inside the IPB brake-by-wire unit. It can cause limp-home mode, loss of brake assist, a hard brake pedal, and ABS/ESC deactivation. Common causes include water ingress or corrosion at the IPB 32-pin/48-pin connector, or internal sensor damage. Visit an authorised dealer for diagnosis and repair. Typical repair cost data is available from recorded cases.
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Cases Logged
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Causes
Likely Causes — Qin Plus
  • 1IPB wiring harness connector (32-pin or 48-pin plug) seal failure. Water ingress after wading or high-pressure washing causes terminal corrosion and oxidation, resulting in intermittent short or open circuits.
  • 2Pressure sensor 1 internal circuit damaged (this sensor usually integrates into the IPB assembly and is not separately serviceable). Possible causes include overvoltage, overheating, or component aging.
  • 3Underbody impact or a detached wiring harness retaining clip causes harness abrasion, shorting the signal wire to body ground or the 12V power supply wire.
  • 4Internal signal processing circuit fault in the IPB controller (ECU hardware fault), preventing the controller from correctly acquiring the sensor analog signal.
  • 5Overdue brake fluid replacement causes excessive water content, leading to fluid leakage at the sensor mount into the electrical connector, resulting in a short circuit and corrosion.
What To Do
  • 1
    Safety Preparation: Disconnect the low-voltage battery negative terminal, remove the high-voltage Manual Service Disconnect (MSD), wait at least 5 minutes to ensure the high-voltage capacitors discharge, and wear insulated gloves and safety goggles.
  • 2
    Visual inspection: Inspect the exterior of the IPB assembly located on the front compartment firewall. Check the wiring harness connector for looseness, backed-out pins, water stains, white corrosion, or signs of brake fluid leakage. Focus on the integrity of the sealing ring.
  • 3
    Power supply and ground verification: Connect the diagnostic tool and turn the ignition switch to ON. Enter the IPB system to 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) (should be less than 1 Ω). Measure the insulation resistance of the signal wire to ground (should be greater than 10 MΩ) and to the 12 V power supply (should be greater than 10 MΩ).
  • 5
    Sensor signal simulation: Use an oscilloscope or diagnostic tool to perform an active test and observe whether 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 the wiring harness is faulty, repair it and apply waterproof insulation. If testing confirms an internal IPB sensor or ECU fault, replace the IPB assembly (retain the original brake hose and bracket). After replacement, use VDS2000/VDS3000 to perform 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 the pressure sensor zero-point calibration and pedal travel calibration. Ensure no air remains.
  • 8
    Functional verification: Clear the fault code and perform a road test. Verify the ABS, ESC, energy recovery, and automatic emergency braking functions operate normally. Confirm C053F00 does not return.
Real-World Cases
BYD DTC AI Analysis

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

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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

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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

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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

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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 Qin Plus 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.B110913DTC B110913 indicates an open signal circuit for the PM2.5 rapid detector (in-cabin air quality sensor). This sensor typically mounts inside the air conditioning system intake duct. It monitors in-cabin PM2.5 concentration in real time and provides data to the automatic air conditioning system for intelligent control of the air purification function. The BYD diagnostic protocol uses sub-code '13' to specifically indicate an open signal circuit. Although this fault theoretically affects a comfort feature, BYD Qin series vehicles classify it as a Level 3 (severe) fault. This classification occurs because the air conditioning system interacts with the battery thermal management system (e.g., monitoring battery cooling intake air quality). The fault can disable the automatic air conditioning mode and prevent the air purification function from operating. In extreme cases, it affects the battery compartment intake air quality assessment, triggering the 'repair immediately' strategy.B110BDTC B110B indicates a fault in the internal air pump (sampling pump) of the PM2.5 air quality detector. This pump draws cabin or outside air into the PM2.5 sensor detection chamber, enabling the laser scattering sensor to measure real-time particulate matter concentration. The air conditioning controller (or BCM) sets this DTC upon detecting an open or short circuit in the pump drive circuit, or abnormal current caused by a seized pump motor. This fault disables the "Green Clean" system, causes the instrument cluster air quality display to read abnormally or disappear, and disables the automatic fresh air/recirculation switching function. It does not affect the vehicle powertrain or core thermal management functions.B173A1ADTC B173A1A indicates the right middle-row side airbag (typically located on the side of the right second-row seat or inside the C-pillar trim panel) igniter circuit resistance measures 0 Ω. In the Supplemental Restraint System (SRS), normal airbag igniter resistance ranges between 2.0 and 5.0 Ω. A resistance of 0 Ω indicates a short to ground or a short between circuit wires, preventing the Airbag Control Unit (ACU) from establishing a normal monitoring circuit. This safety-critical fault prevents the airbag from deploying during a collision, continuously illuminates the instrument panel SRS warning lamp, and may force the entire airbag system into fail-safe mode.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 Qin Plus →Qin Plus 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.