DTC P1172: Secondary Fuel Pump Transfer Malfunction: Description

The secondary fuel pump is located in the rear fuel tank. The secondary fuel pump is powered by a secondary fuel pump relay. Fuel is transferred from the rear fuel tank to the front fuel tank in order to ensure all of the usable fuel volume is available to the primary fuel pump. The secondary fuel pump relay supply voltage is received from the primary fuel pump relay when the primary fuel pump is energized. The secondary fuel pump relay ground is controlled by the Powertrain Control Module (PCM). The secondary fuel pump diagnostic runs only at idle. If the PCM commands the secondary fuel pump ON and a predetermined change inn both the front and rear fuel level sensors does not occur, DTC P1172 sets.