AU
U1332-00

DTC U1332-00 indicates the airbag control unit (SRS ECU) receives an abnormal or timed-out vehicle speed signal via the body CAN bus (B-CAN) — Seal 6 EV

Safety System

DTC U1332-00 indicates the airbag control unit (SRS ECU) receives an abnormal or timed-out vehicle speed signal via the body CAN bus (B-CAN).

This fault occurs when the SRS module fails to receive a valid vehicle speed data frame from the instrument cluster or ABS/ESP module within the predetermined cycle, preventing the airbag system from determining collision severity based on real-time vehicle speed.

This safety system communication fault compromises the collision safety strategy, potentially causing airbag deployment timing deviations during high-speed collisions or false deployments during low-speed collisions.

The U1332-00 fault code on the Seal 6 EV indicates a medium-severity communication problem where the airbag control unit is not receiving a valid vehicle speed signal over the body CAN bus. Common causes include a faulty instrument cluster or gateway, or a damaged CAN transceiver inside the SRS control unit. The recommended fix is to visit an authorised dealer for diagnosis and repair. Typical repair cost data is available from recorded cases.
5
Cases Logged
5
Causes
Likely Causes — Seal 6 EV
  • 1Instrument cluster internal CAN communication module or gateway fault prevents transmission of the vehicle speed signal to the B-CAN network.
  • 2Internal CAN transceiver in the SRS control unit damaged; unable to receive or interpret vehicle speed data frames.
  • 3B-CAN network wiring physical layer fault, including water ingress and oxidation at G10/M40 connectors, harness damage causing a short/open circuit, or excessive contact resistance.
  • 4Abnormal network termination resistance (standard value approximately 60Ω, provided in parallel by the SRS module and instrument cluster module), causing signal reflection or attenuation.
  • 5Use of a non-genuine instrument cluster or SRS module during accident repairs causes a CAN communication protocol mismatch or software version incompatibility.
What To Do
  • 1
    Use the dedicated diagnostic tool to read the fault code and record freeze frame data. Confirm the vehicle speed, time, and environmental conditions when the fault occurred.
  • 2
    Visually inspect the instrument panel vehicle speed display to determine if the fault is a signal source issue (no display on the instrument panel) or a signal transmission issue (instrument panel normal but SRS reports a fault).
  • 3
    Measure the CAN bus voltage at the diagnostic connector: CAN-H should be 2.5-2.7V and CAN-L should be 2.3-2.5V. Verify the bus physical layer base voltage is normal.
  • 4
    Disconnect SRS module connector G10 and measure the terminating resistance between terminals G10-2 (B-CAN-L) and G10-3 (B-CAN-H). The standard value is approximately 60Ω (two 120Ω resistors in parallel). If resistance is abnormal, inspect the wiring section by section.
  • 5
    Check the SRS module power supply (constant power and ignition power) and ground circuits. Verify the voltage drop is less than 0.1V to rule out power supply interference as the cause of the communication interruption.
  • 6
    Use an oscilloscope to monitor the B-CAN waveform. Check for missing data frames, bit errors, ACK errors, or signal distortion. Focus on the G10 connector and the bend in the left A-pillar wiring harness.
  • 7
    Check CAN line insulation. Measure CAN-H and CAN-L resistance to ground and power supply. Inspect for intermittent short circuits due to water ingress corrosion or wiring harness wear.
  • 8
    Perform substitution testing: Replace the instrument cluster or SRS module with a unit of the same model. Observe if the fault code transfers to confirm the faulty component.
  • 9
    After repairing the wiring or replacing the faulty module, clear the fault code and perform a road test to verify the SRS system receives the vehicle speed signal in real time and the warning light is off.
Real-World Cases
BYD DTC AI Analysis

BYD S6 instrument cluster CAN module damage caused loss of vehicle speed signal

✓
The airbag warning light illuminated on the instrument cluster. The scanner retrieved DTC U1332-00. The speedometer displayed normal readings while driving, but the SRS system reported a vehicle speed fault. The technician checked B-CAN network communication with an oscilloscope and found it normal, but found that speed data frames sent from the instrument cluster to the SRS were occasionally lost. The technician traced the fault to the internal CAN communication module in the instrument cluster and replaced the assembly with a genuine part. Fault resolved.
Original source ↗
BYD DTC AI Analysis

BYD NEV precharge resistor failure caused CAN network failure

✓
The vehicle presented with a powertrain fault and multiple CAN communication DTCs including U1332-00. Diagnosis found a damaged front-end pre-charge resistor in the high-voltage battery pack, disrupting communication between the BMS and vehicle controller and affecting vehicle speed signal transmission across the CAN network. Replaced the pre-charge resistor and performed cell balancing on the battery pack. Network communication returned to normal and the U1332 DTC cleared.
Original source ↗
BYD DTC AI Analysis

Protocol mismatch caused by non-genuine instrument cluster in accident-repaired vehicle

✓
After accident repairs, the airbag warning light stayed on. Retrieved DTC U1332-00. Inspection found an aftermarket instrument cluster installed during the repair. The speedometer displayed correctly, but the cluster’s CAN protocol differed from the SRS module’s, so the SRS could not parse the vehicle speed data. Replaced the cluster with an OEM unit and reconfigured the SRS system parameters. Fault resolved.
Original source ↗
BYD DTC AI Analysis

BYD S6 left A-pillar wiring harness damage causing intermittent CAN-L short circuit

✓
On starting the vehicle after parking, the airbag warning light illuminated with DTC U1332-00 stored. Inspection found water stains on the G10 connector. Further investigation revealed the wiring harness beneath the left A-pillar had insulation damage from a previous accident repair, contacting the body metal and causing an intermittent short to ground on the CAN-L line. Repaired the damaged wiring, cleaned oxidation from the connector and applied waterproofing. Fault cleared.
Original source ↗
BYD DTC AI Analysis

Internal transceiver damage in SRS control unit caused vehicle-wide communication failure

✓
Multiple warning lights (ABS, SRS, ESP) illuminated simultaneously while driving. Scanner retrieved communication fault codes including U1332-00 and U0140. Using segmented troubleshooting, disconnected the SRS module; other systems returned to normal. Confirmed faulty CAN transceiver inside the SRS control unit continuously transmitting error frames and paralyzing the B-CAN network. Replaced the SRS control unit, recoded and matched it to the vehicle. Fault completely resolved.
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.