BYD ATTO 3 (e-Platform 3.0) B2ABC16 AC Compressor High-Voltage Side Low-Voltage Fault

B2ABC16 indicates that a low-voltage condition has been detected on the high-voltage side of the electric A/C compressor. The fault affects the compressor’s high-voltage power supply and drive electronics, which provide the electrical energy required to operate the compressor motor and maintain refrigerant circulation for cabin cooling. The BYD ATTO 3 uses BYD’s e-Platform 3.0 architecture, with this generation introduced from 2022 and continuing onward.

Symptoms

• Air conditioner does not produce cold air
• Electric compressor fails to start
• A/C cooling may be weak or intermittent
• Compressor may stop unexpectedly
• Climate control warning may be displayed
• Cabin temperature remains higher than requested
• High-voltage HVAC fault codes may be stored
• Compressor operation may be disabled as a protective measure

Possible Causes

• Insufficient high-voltage supply to the A/C compressor
• High-voltage battery voltage or power-delivery fault
• High-voltage distribution system fault
• Damaged high-voltage compressor wiring
• Loose or poorly connected high-voltage connector
• High resistance in the compressor power circuit
• Internal compressor inverter or power-electronics fault
• High-voltage interlock or safety-system issue
• Low 12V auxiliary system voltage affecting compressor control
• Compressor control-module fault
• Electrical protection or shutdown event
• Thermal-management system fault

Diagnosis

Diagnosis should begin by confirming B2ABC16 and checking for related high-voltage battery, power-distribution, compressor, and electrical-system faults. High-voltage supply data, compressor operating status, voltage-related parameters, connector condition, wiring integrity, and relevant control-module information should then be evaluated against manufacturer specifications.

The diagnostic direction should establish whether the low-voltage condition originates from the vehicle high-voltage supply, distribution circuit, wiring, compressor electronics, or control system before replacing components. Because the A/C compressor operates on the vehicle’s high-voltage system, manufacturer isolation procedures and appropriate EV safety equipment are essential during diagnosis.

For New Zealand owners, confirming the source of the voltage loss before replacing high-voltage HVAC 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.