Fuel Balance Module Control System (Dual Tanks)

FUEL BALANCE CONTROL SYSTEM

The 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 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.

FUEL PUMP BALANCE MODULE
The Fuel Pump Balance Module relies on input from the primary and secondary fuel senders, and cannot operate if the fuel gauge is not working properly.

For Fuel Pump Balance Module testing and inspection refer to Instrument Panel, Gauges and Warning Indicators / Symptom Releated Diagnostic Procedures / Fuel Gauge Symptom Related Diagnostic Procedures

For Fuel Pump Balance Module electrical diagrams refer to Instrument Panel, Gauges and Warning Indicators / Diagrams / Electrical. Diagrams