U0155Średni
Utrata komunikacji z modułem wspomagania (EPS)
Komunikacja sieciowa
Sprawdź szczegóły →U0240
ŚredniLost Communication with HVAC (Heating, Ventilation, and Air Conditioning) Control Module. The code indicates a missing CAN bus signal between the central controller and the climate control module.
OBD-II (EN): Lost Communication with HVAC Control Module
Code U0240 means lost communication between the central CAN bus and the HVAC (climate control) module. The cause could be a damaged harness, poor contact in the connector, or a fault in the HVAC controller itself. Due to the complexity of CAN network diagnostics, verification at a workshop with a bus analyzer is recommended.
Symptoms
No operation or incorrect operation of air conditioning and heating; climate control panel unresponsive to commands; automatic temperature regulation disabled; possible illumination of CHECK ENGINE or HVAC warning light on the dashboard; sporadic loss of communication with other modules on the CAN network.
Possible causes
• Damage or open circuit in CAN bus wires (High/Low) leading to the HVAC module • Corrosion or loose electrical connection at the climate control module plug • Faulty or defective HVAC control module (internal controller failure) • Short circuit on the CAN line causing disruptions across the entire network • Insufficient module supply voltage (faulty fuse or relay supplying HVAC) • Damaged CAN bus terminator (120 Ω resistor)
Affected systems
Magistrala CANModuł sterowania klimatyzacją (HVAC)System ogrzewania i wentylacjiSieć komunikacyjna pojazduPanel sterowania klimatronikiem
Related codes
B1000Wysoki
Moduł sterowania nadwoziem (BCM) — usterka wewnętrzna
Nadwozie
Sprawdź szczegóły →U0100Krytyczny
Utrata komunikacji z ECM (sterownik silnika)
Komunikacja sieciowa
Sprawdź szczegóły →U0001Krytyczny
Magistrala CAN High Speed — brak komunikacji
Komunikacja sieciowa
Sprawdź szczegóły →Suggested Hybspec services
Based on the systems affected by this code, we will most likely start with:
Does code U0240 require professional diagnostics?
The code alone is not enough. To find the cause, you need to read live data, check freeze frame conditions, and compare with vehicle behavior. Book a diagnostic session.