Error codes › Diesel Air Heaters › Webasto SmarTemp Control 3.0 / 4.0 (controller display - not a heater code) › Low voltage warning (LED + message)
Webasto SmarTemp Control 3.0 / 4.0 (controller display - not a heater code) error code Low voltage warning (LED + message)
SmarTemp's own Low Voltage Disconnect (LVD): supply at or below the LVD setting. The warning (status LED and message) appears after 8 minutes of low voltage and stays 2 minutes, then the SmarTemp switches the heater off. At or below the setting + 0.1 V the heater will not start. Default setting 11.4 V (12 V) / 24.2 V (24 V); adjustable 11-12.5 V / 21-25.5 V; can be disabled (disables only the SmarTemp's internal LVD).
What to check, and in what order, is in the app. The flow Webasto SmarTemp Control 3.0 / 4.0 - fault display, lock-out, low-voltage disconnect walks this code step by step with the pass/fail measurements, wiring schematics and procedures that go with it, and it works offline in the bay.
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- Webasto SmarTemp Control 4.0 Installation - Operating Instructions (Org. 6/2026)Webasto Thermo & Comfort North America
- Webasto SmarTemp Control 3.0 / 3.0 Bluetooth Installation - Operating Instructions, P/N 5013872B (Org. 12/2022, Rev. 6/2026)Webasto Thermo & Comfort North America