2008 GMC Yukon Denali

P069E GMC - Fuel Pump Control Module Requested MIL Illumination...Possible causes; Faulty Fuel Pump, Faulty Fuel Pump Control Module, Fuel Pump Control Module harness is open or shorted, Fuel Pump Control Module circuit poor electrical connection...P069E CHEVROLET Description; The fuel pump control module uses the serial data network to signal the Engine Control Module (ECM) that the fuel pump control module is requesting malfunction indicator lamp (MIL) illumination. A DTC is set in the fuel pump control module, and the request for MIL illumination is sent when the fuel pump control module determines that a failure that affects emissions has occurred in the fuel pump control system. When the ECM receives the message from the fuel pump control module, DTC P069E will set in the ECM.......P0191 GMC - Fuel Rail Pressure Sensor Circuit Range/Performance...Possible causes; Low or no fuel, Faulty Rail Pressure (FRP) Sensor, Faulty Rail Pressure (FRP) harness is open or shorted, Faulty Rail Pressure (FRP) circuit poor electrical connection, Faulty Fuel Pump...Description; The Fuel Rail Pressure (FRP) sensor has a 5-volt reference circuit, a signal circuit, and a low reference circuit. The Engine Control Module (ECM) monitors the voltage on the FRP sensor circuits. When the fuel pressure is high, the signal voltage is high. When the fuel pressure is low, the signal voltage is low. The fuel pressure regulator has a solenoid supply voltage circuit and a solenoid control circuit. The ECM controls the fuel pressure regulator, which regulates high pressure fuel that goes to the fuel injector rails and the injectors.