Fuel Pump Electronic Control Unit (ECU) & Fuel Pump Switch (Land Cruiser & LX470)
Fuel pump operating speed is controlled by the operating condition of the engine such as: starting, idling, light load or heavy load. The Engine Control Module (ECM) delivers an input signal from FPC terminal on ECM to FPC terminal on fuel pump ECU in accordance with the engine operating condition. The fuel pump ECU uses this input signal to determine how much voltage should be delivered to the fuel pump for varying fuel pump operating speed. If a problem exists in fuel pump ECU or control circuit, a Diagnostic Trouble Code (DTC) P1200 may be stored in the ECM. See TESTS W/CODES article for retrieving and servicing of any DTCs. Fuel pump ECU is located behind inner panel, just behind driver's side rear wheelwell. See Fig 1.
The fuel pump switch is in the circuit between FPC terminal on ECU and FPC terminal on fuel pump ECU. If the vehicle is involved in a collision, the fuel pump switch will shut off the fuel pump by opening this circuit, and not allowing any input signal to be delivered from ECM to fuel pump ECU. Fuel pump switch is located on driver's side of instrument panel. See Fig 2. Fuel pump switch contains a reset switch which has an OFF and ON position. See Fig 2. Continuity will exist between electrical terminals on fuel pump switch with reset switch in the ON position, and no continuity in the OFF position. Reset switch must be in ON position for fuel pump operation.