NO
AU
B132213

This fault code indicates an open circuit in the signal circuit of the pressure/temperature sensor at the Plate Heat Exchanger (PHE) outlet — Seal U

Thermal Management System

This fault code indicates an open circuit in the signal circuit of the pressure/temperature sensor at the Plate Heat Exchanger (PHE) outlet.

In the BYD heat pump thermal management system, the Plate Heat Exchanger is the core component for heat exchange between the refrigerant and the motor coolant.

The outlet pressure sensor monitors the refrigerant pressure (or integrated temperature) after heat exchange, providing closed-loop control data for the Electronic Expansion Valve (EXV) and the electric compressor.

An open circuit fault indicates the control unit (air conditioning controller or thermal management module) detects a continuous sensor signal voltage above 4.8V (typically corresponding to an unshunted 5V reference voltage).

Without real-time pressure data, the system triggers thermal management protection mode.

This mode disables the heat pump function, limits motor power output, and in extreme cases, prohibits high-voltage power-up to prevent heat exchanger overpressure damage or abnormal refrigerant circulation.

5
Cases Logged
Real-World Cases
BYD DTC AI Analysis

Intermittent open circuit in plate heat exchanger pressure sensor on Qin Pro DM after wading

✓
The air conditioning stopped producing heat after the vehicle drove through water. DTC B132213 stored. Inspection revealed water inside the plate heat exchanger outlet pressure sensor connector, with the pins oxidised and blackened. The connector seal failed due to water surge while wading. Cleaned the oxidised pins, replaced the seal, and fitted waterproof corrugated tubing to the wiring harness. Fault resolved.
BYD DTC AI Analysis

Qin EV300: Wiring harness wear caused open circuit after accident repair

✓
Following right-front collision repairs, B132213 would set intermittently while driving. Inspection found the accident repair had incorrectly secured the harness, causing the plate heat exchanger sensor wiring to chafe against the sharp edge of the right front chassis rail. The insulation wore through and the signal wire (one of three copper cores) completely fractured. Repaired the damaged harness, sealed with heat shrink tubing, re-routed and secured the clips to specification, and fitted a protective sleeve to prevent chafing.
BYD DTC AI Analysis

False open circuit caused by a loose thermal management controller connector

✓
Vehicle has no accident history. Heat pump system suddenly failed. Diagnostics showed the pressure sensor had normal power supply but the signal voltage remained at 5V. Investigation revealed the 32-pin connector on the thermal management controller (under the centre console) was not fully locked, possibly loosened when stepped on during transport or repairs. Reseated and secured the connector; fault cleared.
BYD DTC AI Analysis

Cracked internal PCB in sensor body caused open circuit at low temperatures

✓
In cold northern winter weather, the vehicle could not start the heat pump; the fault disappeared in a warm garage. Disassembly revealed that the internal PCB solder joint of the plate heat exchanger outlet pressure sensor cracked due to low-temperature contraction, causing a signal open circuit. Replaced the OEM pressure-temperature sensor assembly and verified the fault was cleared in a -20°C environmental chamber.
BYD DTC AI Analysis

Hidden open circuit caused by water ingress and corrosion in the adapter plug

✓
DTC appeared intermittently. Tapping the inner fender wiring harness reproduced the fault. Inspection found water ingress at the firewall connector (BJ02) due to perished sealing rubber. The pressure sensor signal wire had corroded and broken at the connector terminal. Replaced the connector assembly, repaired the corroded wiring harness, and resealed the firewall penetration with sealant.
Other Seal U 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.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.B110AThis DTC indicates interrupted CAN bus communication or abnormal data between the air conditioning control unit (ACU) and the PM2.5 air quality sensor. The PM2.5 sensor monitors particulate concentration inside and outside the vehicle and provides the basis for purification control in the automatic air conditioning system. The ACU triggers this fault if it fails to receive a valid CAN message from the sensor within the specified period (usually 100-500 ms), if message verification fails, or if the signal frame times out. Although this fault does not affect vehicle driving safety, it disables the automatic air purification function. The air conditioning system cannot automatically switch between recirculation and fresh air modes or activate the air purification mode based on air quality. A persistent fault may restrict the thermal management strategy.
Data confidence: Community This information is for reference only. Always consult a qualified technician for diagnosis and repair. Do not attempt high-voltage system repairs yourself.