BYD ATTO 3 (e-Platform 3.0) B1B5100 Rear Left Parking Sensor Internal Fault

B1B5100 indicates an internal fault has been detected in the rear left parking sensor. The fault affects the parking assistance system, which uses ultrasonic sensors to detect nearby obstacles and provide distance information to the parking control system. The BYD ATTO 3 uses BYD’s e-Platform 3.0 architecture, with this generation introduced from 2022 and continuing onward.

Symptoms

• Parking sensor warning displayed
• Rear parking assistance may be unavailable
• Rear left sensor may not detect nearby obstacles
• Incorrect or missing distance warnings
• Parking sensor alerts may be intermittent
• Multiple parking assistance functions may be restricted
• B1B5100 stored in the parking assistance system
• Parking sensor system may be disabled

Possible Causes

• Internal failure of the rear left parking sensor
• Damaged ultrasonic sensor
• Water or moisture intrusion into the sensor
• Damaged sensor connector
• Loose or poorly seated connector terminals
• Corrosion affecting the sensor circuit
• Open or short circuit in the sensor wiring
• Physical damage to the rear bumper or sensor
• Incorrect sensor installation or positioning
• Parking control-module fault
• Low or unstable 12V system voltage

Diagnosis

Diagnosis should begin by confirming B1B5100 and checking whether the fault remains associated with the rear left sensor during a system scan. The sensor’s electrical supply, wiring, connector condition, sensor response, mounting position, and parking control-module data should then be assessed against manufacturer specifications.

The sensor surface and bumper mounting area should also be inspected for contamination, impact damage, or incorrect positioning before determining whether the sensor itself has failed. For New Zealand owners, confirming the sensor and circuit fault before replacing the parking sensor can help avoid unnecessary repair costs.

Accurately diagnosing this fault often requires manufacturer testing procedures, wiring diagrams, connector pinouts, specifications, and system calibration information. Access to the factory service manual significantly reduces diagnostic time and helps prevent unnecessary parts replacement.

Applicable Years

2022, 2023, 2024, 2025, 2026, onwards

To order the correct OEM Service and Repair Manual for your BYD ATTO 3, submit your request using the form below and our team will provide the ordering details.