A compact DIY solution to automatically reactivate a vehicle preheater (e.g. VW T5) during cold conditions.

This project is a simple proof-of-concept (PoC) designed to automate the activation of a vehicle’s preheater remote.

Instead of modifying the vehicle or the heating system itself, this setup physically presses the remote button using a servo motor — triggered based on ambient temperature.

The system operates fully offline and is built with inexpensive, widely available components.

• The preheater remote is configured to run for 120 minutes
• The system checks the ambient temperature every 2 minutes
• If the temperature drops below 19°C, a servo motor presses the remote button
• This restarts the heating cycle
• The process repeats indefinitely

• Fully autonomous operation
• No modification of vehicle electronics required
• Low-cost and easy to replicate
• Modular and extendable design

• Arduino Nano
• Servo Motor (e.g. HS-303)
• DHT11 Temperature Sensor
• 3× M5x20 screws
• Wires
• Solder + soldering iron
• PLA filament for 3D printing

The enclosure is designed for standard FDM 3D printing.

Material: PLA
Estimated print time: ~4 hours

• Infill:

  • 20% for all parts
  • 100% for Mid_ButtonTrigger

• Layer Height:

  • 0.3 mm

• Supports:

  • Not required

The control logic is intentionally simple:

1. Wait for the current heating cycle to complete (120 minutes)
2. Check temperature every 2 minutes
3. If temperature < 19°C → trigger servo → press button
4. Repeat loop

This project is licensed under the
Creative Commons Attribution 4.0 International (CC BY 4.0) License.

You are free to:

• Use
• Modify
• Distribute

As long as proper credit is given.

Full license text: https://creativecommons.org/licenses/by/4.0/

This project is a proof-of-concept and provided "as is".

• No guarantee of reliability or safety
• Use at your own risk
• Not intended for critical or safety-relevant systems