38.0
Internal Fault: Serial port initialization error
Danfoss · VLT HVAC Drive FC 102
What does 38.0 mean?
The internal serial communication port failed to initialize upon power-up or during operation. This can prevent communication with the LCP or external serial devices, indicating a possible internal hardware or firmware issue with the control board.
Common Causes
- Local Control Panel (LCP) connection issues; LCP cable is damaged or not fully seated.
- Faulty LCP module preventing proper communication with the drive's control board.
- Internal serial communication hardware (UART chip) on the control board has failed.
- Severe EMI interfering with the internal serial communication lines during initialization.
Repair Steps & Checklist
Click steps to track your progress.
- 1
1. Power down the drive, then remove and firmly re-seat the LCP on its connector.
- 2
2. Attempt to operate the drive with a different, known-good LCP, if available, to rule out LCP module failure.
- 3
3. Visually inspect the LCP connector on the control board for bent pins or signs of damage.
- 4
4. If the fault persists, replacement of the control board is likely required due to internal serial port hardware failure.
Verified technical data. Last updated: March 2026
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Source: Danfoss VLT HVAC Drive FC 102