Invalid Data from Headlamp Control Module B
The receiving control module (typically the BCM, gateway, or powertrain control module) has detected that data received from the Headlamp Control Module 'B' over the communication bus (CAN, LIN, or other) is invalid. This means the message arrived, but its content failed integrity checks (checksum/CRC), contains out-of-range values, or the rolling counter is incorrect.
1. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.
2. Most Common Causes
- Damaged wiring or connectors (open, short, corrosion) on the communication bus to the Headlamp Module 'B'
- Internal failure of the Headlamp Control Module 'B' (hardware or firmware)
- Software or calibration mismatch between the Headlamp Module 'B' and the receiving module
- Low battery voltage or voltage spikes corrupting communication
- Electromagnetic interference (EMI) on the data bus
3. Symptoms You Will Notice
- Malfunction indicator lamp (MIL) illuminated
- Headlamp system issues (e.g., flickering, no operation, or incorrect aiming)
4. Step-by-Step Diagnosis
Scan for all stored codes and freeze frame data
Inspect the communication bus wiring and connectors for damage, corrosion, or loose connections
Check battery voltage and charging system for proper operation
Test the Headlamp Control Module 'B' for internal faults using manufacturer-specific diagnostics
Verify software versions and compatibility between modules
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, it is generally safe to drive, but headlamp function may be compromised. Have the issue diagnosed promptly to ensure proper lighting and avoid further electrical problems.
How much does it cost to fix?▼
Repair costs typically range from $100 to $600, depending on whether the issue is a wiring repair ($100-$200) or module replacement ($300-$600).