Fuel Balance Control System (Dual Tanks)
DESCRIPTIONThe fuel balance control system consists of the following components:
- Front (main) fuel tank sender.
- Rear (auxiliary) fuel tank sender.
- Balance fuel pump.
- Balance fuel pump relay.
- Fuel sender and balance module.
On vehicles with dual tanks, the front tank is the main and the rear tank is the auxiliary. The main fuel balance pump supplies fuel to the fuel injection unit. The low pressure (about 32 kPa or 7 psi) fuel balance pump is used only to transfer fuel from the auxiliary tank to the main tank in order to balance the fuel levels in both tanks. As the main tank level drops to about 25 % below the level in the auxiliary tank, the fuel sender and balance module energizes the fuel pump relay. This pumps the fuel from the auxiliary tank to the main tank. When the level in the main tank reaches a level slightly higher than the level in the auxiliary tank, or the auxiliary tank is empty, the module de-energizes the balance pump relay and fuel pump. Any malfunction in either of the fuel gage circuits will disable the system and the fuel will not be transferred from the main fuel tank to the auxiliary fuel tank.