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.
Diagnostic Trouble Code (DTC) Information HCM-Dd11
Condition
The Headlamp Control Module (HCM) both transmits and receives information via a standardized serial communication method - LIN (Local Interconnect Network). The control module checks the communication with the Right headlamp control unit (RHCU).
The diagnostic trouble code (DTC) is stored if the control module detects that:
- No communication with the Right headlamp control unit (RHCU).
The control module's test for the diagnostic trouble code (DTC) starts in the event of:
- Activated control module.
The control module can only detect the fault once the test has been started and the diagnostic trouble code (DTC) is stored when the conditions are met.
NO RELATED
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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.