Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2007 Volvo XC90 4.4 85FACTORY OEM SERVICE PROCEDURE
Headlamp Control Module (HCM) DTCS
HEADLAMP CONTROL MODULE (HCM) - DTC INDEX
| DTC | Description |
|---|---|
| HCM-0141 | Control module. Internal fault (B5254T2) |
| HCM-0317 | Battery voltage. Voltage too high (B5254T2) |
| HCM-2281 | Communication, Central Electronic Module (CEM). Signal missing (B5254T2) |
| HCM-2687 | Communication with SAS control module. Signal missing (B5254T2) |
| HCM-2987 | Communication with BCM control module. Signal missing (B5254T2) |
| HCM-4076 | Lamp unit Wrong mounting position (B5254T2) |
| HCM-6401 | Left headlamp swivelling motor circuit Faulty signal (B5254T2) |
| HCM-6411 | Left-hand lamp module (LHCU) Voltage too low (B5254T2) |
| HCM-6477 | Left headlamp swivelling motor circuit Commanded position not reachable (B5254T2) |
| HCM-6501 | Right headlamp swivelling motor circuit Faulty signal (B5254T2) |
| HCM-6511 | Rright-hand lamp module (RHCU) Voltage too low (B5254T2) |
| HCM-6577 | Right headlamp swivelling motor circuit Commanded position not reachable (B5254T2) |
| HCM-B104076 | Lamp Unit. Mechanical Failures. Wrong mounting position (B6324S) |
| HCM-B104076 | Lamp Unit. Mechanical Failures. Wrong mounting position (B8444S) |
| HCM-B1D6401 | Left Headlamp Swivelling Motor Circuit. General Failure Information. General electrical failure (B6324S) |
| HCM-B1D6401 | Left Headlamp Swivelling Motor Circuit. General Failure Information. General electrical failure (B8444S) |
| HCM-B1D6477 | Left Headlamp Swivelling Motor Circuit. Mechanical Failures. Commanded position not reachable (B6324S) |
| HCM-B1D6477 | Left Headlamp Swivelling Motor Circuit. Mechanical Failures. Commanded position not reachable (B8444S) |
| HCM-B1D6501 | Right Headlamp Swivelling Motor Circuit. General Failure Information. General electrical failure (B6324S) |
| HCM-B1D6501 | Right Headlamp Swivelling Motor Circuit. General Failure Information. General electrical failure (B8444S) |
| HCM-B1D6577 | Right Headlamp Swivelling Motor Circuit. Mechanical Failures. Commanded position not reachable (B6324S) |
| HCM-B1D6577 | Right Headlamp Swivelling Motor Circuit. Mechanical Failures. Commanded position not reachable (B8444S) |
| HCM-B1D6616 | Left Headlamp Power Module. General Electrical Failures. Circuit voltage below threshold (B6324S) |
| HCM-B1D6616 | Left Headlamp Power Module. General Electrical Failures. Circuit voltage below threshold (B8444S) |
| HCM-B1D6716 | Right Headlamp Power Module. General Electrical Failures. Circuit voltage below threshold (B6324S) |
| HCM-B1D6716 | Right Headlamp Power Module. General Electrical Failures. Circuit voltage below threshold (B8444S) |
| HCM-DD00 | Communication with left-hand lamp module (LHCU) Faulty signal (B5254T2) |
| HCM-DD01 | Communication with left-hand lamp module (LHCU) Signal missing (B5254T2) |
| HCM-DD02 | Communication with left-hand lamp module (LHCU) Faulty signal (B5254T2) |
| HCM-DD10 | Communication with left-hand lamp module (LHCU) Signal missing (B5254T2) |
| HCM-DD20 | Communication with right-hand lamp module (RHCU) Faulty signal (B5254T2) |
| HCM-DD21 | Communication with right-hand lamp module (RHCU) Signal missing (B5254T2) |
| HCM-DD22 | Communication with right-hand lamp module (RHCU) Faulty signal (B5254T2) |
| HCM-DD30 | Communication with right-hand lamp module (RHCU) Signal missing (B5254T2) |
| HCM-E000 | Control module communication. Faulty communication (B5254T2) |
| HCM-E003 | Configuration fault. Faulty configuration (B5254T2) |
| HCM-E010 | Control module. Voltage too low (B5254T2) |
| HCM-P060141 | Internal Control Module Memory Check Sum Error. System Internal Failures. General checksum failure (B6324S) |
| HCM-P060141 | Internal Control Module Memory Check Sum Error. System Internal Failures. General checksum failure (B8444S) |
| HCM-U000100 | High Speed CAN Communication Bus. General Failure Information. No sub type information (B6324S) |
| HCM-U000100 | High Speed CAN Communication Bus. General Failure Information. No sub type information (B8444S) |
| HCM-U012687 | Lost Communication With Steering Angle Sensor Module. Bus Signal/Message Failures. Missing message (B6324S) |
| HCM-U012687 | Lost Communication With Steering Angle Sensor Module. Bus Signal/Message Failures. Missing message (B8444S) |
| HCM-U012987 | Lost Communication With Brake Control Module. Bus Signal/Message Failures. Missing message (B6324S) |
| HCM-U012987 | Lost Communication With Brake Control Module. Bus Signal/Message Failures. Missing message (B8444S) |
| HCM-U030000 | Internal Control Module Software Incompatibility. General Failure Information. No sub type information (B6324S) |
| HCM-U030000 | Internal Control Module Software Incompatibility. General Failure Information. No sub type information (B8444S) |
| HCM-U042281 | Invalid Data Received From Central electronic module. Bus Signal/Message Failures. Invalid serial data received (B6324S) |
| HCM-U042281 | Invalid Data Received From Central electronic module. Bus Signal/Message Failures. Invalid serial data received (B8444S) |
| HCM-U054283 | Invalid Data Received From Headlamp Control Module "A". Bus Signal/Message Failures. Value of signal protection calculation incorrect (B6324S) |
| HCM-U054283 | Invalid Data Received From Headlamp Control Module "A". Bus Signal/Message Failures. Value of signal protection calculation incorrect (B8444S) |
| HCM-U054286 | Invalid Data Received From Headlamp Control Module "A". Bus Signal/Message Failures. Signal invalid (B6324S) |
| HCM-U054286 | Invalid Data Received From Headlamp Control Module "A". Bus Signal/Message Failures. Signal invalid (B8444S) |
| HCM-U054288 | Invalid Data Received From Headlamp Control Module "A". Bus Signal/Message Failures. Bus off (B6324S) |
| HCM-U054288 | Invalid Data Received From Headlamp Control Module "A". Bus Signal/Message Failures. Bus off (B8444S) |
| HCM-U054383 | Invalid Data Received From Headlamp Control Module "B". Bus Signal/Message Failures. Value of signal protection calculation incorrect (B6324S) |
| HCM-U054383 | Invalid Data Received From Headlamp Control Module "B". Bus Signal/Message Failures. Value of signal protection calculation incorrect (B8444S) |
| HCM-U054386 | Invalid Data Received From Headlamp Control Module "B". Bus Signal/Message Failures. Signal invalid (B6324S) |
| HCM-U054386 | Invalid Data Received From Headlamp Control Module "B". Bus Signal/Message Failures. Signal invalid (B8444S) |
| HCM-U054388 | Invalid Data Received From Headlamp Control Module "B". Bus Signal/Message Failures. Bus off (B6324S) |
| HCM-U054388 | Invalid Data Received From Headlamp Control Module "B". Bus Signal/Message Failures. Bus off (B8444S) |
| HCM-U1A3887 | Lost Communication With Left Headlamp Module. Bus Signal/Message Failures. Missing message (B6324S) |
| HCM-U1A3887 | Lost Communication With Left Headlamp Module. Bus Signal/Message Failures. Missing message (B8444S) |
| HCM-U1A3987 | Lost Communication With Right Headlamp Module. Bus Signal/Message Failures. Missing message (B6324S) |
| HCM-U1A3987 | Lost Communication With Right Headlamp Module. Bus Signal/Message Failures. Missing message (B8444S) |
| HCM-U300316 | Battery Voltage. General Electrical Failures. Circuit voltage below threshold (B6324S) |
| HCM-U300316 | Battery Voltage. General Electrical Failures. Circuit voltage below threshold (B8444S) |
| HCM-U300317 | Battery Voltage. General Electrical Failures. Circuit voltage above threshold (B6324S) |
| HCM-U300317 | Battery Voltage. General Electrical Failures. Circuit voltage above threshold (B8444S) |
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.