BYD ATTO 3 (e-Platform 3.0) B22A813 Exterior Trunk Detection Antenna Open Circuit

B22A813 indicates an open circuit has been detected in the exterior trunk detection antenna circuit. The fault affects the smart key and keyless entry system, where the exterior trunk antenna detects an authorised key near the rear of the vehicle to support keyless access and related tailgate functions. The BYD ATTO 3 uses BYD’s e-Platform 3.0 architecture, with this generation introduced from 2022 and continuing onward.

Symptoms

• Smart key may not be detected near the rear of the vehicle
• Keyless tailgate or trunk access may not operate correctly
• Exterior trunk access function may operate intermittently
• Vehicle may not respond when the smart key is near the rear of the vehicle
• Smart key detection warning may be displayed
• B22A813 stored in the keyless entry control system
• Other exterior antenna faults may be present
• Passive entry functions may remain available at other vehicle locations

Possible Causes

• Open circuit in the exterior trunk detection antenna wiring
• Faulty exterior trunk detection antenna
• Loose or disconnected antenna connector
• Damaged connector terminals
• Corrosion or poor electrical contact
• Damaged wiring near the rear of the vehicle
• Incorrectly installed or damaged antenna
• Low or unstable 12V system voltage
• Keyless entry control-module fault
• Communication fault affecting antenna operation

Diagnosis

Diagnosis should begin by confirming B22A813 and checking whether the smart key is detected correctly at other exterior locations. The exterior trunk antenna circuit, connector condition, wiring continuity, antenna status, power supply, and relevant control-module communication should then be evaluated against manufacturer specifications. Comparing the affected antenna with other exterior detection antennas can help determine whether the fault is isolated to the antenna assembly or its wiring.

For New Zealand owners, confirming the antenna circuit before replacing keyless entry components 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.