Headlamp Control Module Performance
The headlamp control module isn't responding as expected.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The computer controls your headlights, and it's not getting the right signals or timing from the headlamp control module, which affects how your headlights operate.
What the computer is actually seeing
The computer monitors the input and output of the headlamp control module, looking for proper voltage and response times. If it sees voltage inconsistencies or delays beyond 300 milliseconds in response, it triggers this code.
What a healthy reading looks like
Expected voltage at the headlamp control module should be between 9V to 14V; response time should be quicker than 300 milliseconds on activation.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check battery voltage; should be between 12.4V and 12.8V with the engine off. If low, charge or replace the battery.
- 22. Inspect the headlamp control module connectors for corrosion or loose wires. Repair as needed.
- 33. Use a multimeter to check the voltage at the headlamp control module; it should read between 9V and 14V. If not, trace back the wiring to find breaks or shorts.
- 44. Monitor the response time of the headlamp control module operation using a scan tool. It should respond within 300 milliseconds. If not, the module may be faulty.
- 55. Check the headlight switch operation; ensure that it's functioning correctly. Replace if any faults are found.
Common causes
- Faulty headlamp control module
- Wiring issues or shorts in the harness
- Corroded connectors
- Battery voltage below 9V
- Faulty headlight switches
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Yes, it's generally safe to drive, but headlights may work improperly, so fix it soon.
Will this code come back after clearing?
If the underlying issue isn't addressed, the code will likely return.
Why does this code appear alongside others?
Different codes for the headlamp control module can indicate related issues, like wiring or component failures, all affecting headlight performance.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
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