What Does the Land Cruiser Sub Tank Switch Do?
Some Toyota Land Cruiser models are equipped with a dual fuel tank system that includes a main tank and a sub (secondary) tank. The sub-tank switch allows the driver to control the transfer of fuel from the sub-tank to the main tank during operation.
Purpose of the Sub Tank Switch
The sub-tank switch activates a fuel transfer pump that moves fuel from the sub-tank into the main tank. This system does not switch the engine’s fuel source directly between tanks; instead, it ensures the main tank stays filled from the secondary supply when needed.
How It Works
- When the sub-tank switch is pressed, a transfer pump engages
- Fuel is moved from the sub-tank to the main tank only
- The switch may have an indicator light to show that the transfer is in progress
- Once the sub-tank is empty, the system typically automatically stops the transfer
Some models also display fuel levels for both tanks on the instrument panel, while others only show the main tank’s level.
Models That Use This System
- Land Cruiser 70 Series (select commercial and expedition models)
- Land Cruiser 80 Series
- Land Cruiser 100 Series (some diesel variants)
- Global-market models intended for long-distance or remote travel
- Australian, African, and Middle Eastern versions are most likely to include this feature
Why It’s Useful
- Extends driving range without the need for external fuel containers
- Adds redundancy in case of tank failure or fuel contamination
- Ideal for remote or off-road travel where fuel stations are limited
- Improves weight distribution by allowing selective fuel transfer