Fuel voltage regulator low help

2007 Chevrolet Silverado - 2WD or 4X4
2007 Chevrolet Silverado Classic - 4WD or 2WD . What size engine ?
Engine Controls and Fuel - 4.3L
Engine Controls and Fuel - 4.8L, 5.3L, and 6.0L
Engine Controls and Fuel - 6.6L (LBZ and LLY)
Engine Controls and Fuel - 8.1L

6.6 L
DTC P0191: Fuel Rail Pressure (FRP) Sensor Performance
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.

Your vehicle has no fuel pump relay . Has a fuel pump flow control module .
Fuel Pump Flow Control Module (FPCM)
The fuel pump flow control module (FPCM) is a serviceable GMLAN module. The FPCM receives the desired fuel pressure message from the engine control module (ECM) and controls the fuel pump located within the fuel tank to achieve the desired fuel pressure. The FPCM sends a PWM signal to the fuel pump, and pump speed is changed by varying the duty cycle of this signal.
Plus it has two fuel pumps !
The high pressure fuel pump (9) is a mechanical one cylinder design driven by an eccentric on the exhaust camshaft (1) of bank 2. High pressure fuel is regulated by the fuel rail pressure (FRP) regulator, which is a part of the high pressure fuel pump. The FRP regulator is a magnetic actuator which controls the inlet valve of the high pressure pump. The ECM provides battery voltage on the actuator high circuit and ground on the actuator low reference circuit. Both circuits are controlled by the ECM. When the ECM deactivates the FRP regulator, both circuits are disabled and the inlet valve is held open with spring pressure. When the ECM activates the FRP regulator, the low circuit driver connects the low reference circuit to ground and the high circuit driver pulse-width modulates (PWM) the high circuit. The ECM uses the camshaft and crankshaft position sensor inputs to synchronize the FRP regulator with the position of the eccentric on the camshaft. The ECM regulates fuel pressure by adjusting the portion of each pump stroke that provides fuel to the rail. The high pressure fuel pump also contains an integrated pressure relief valve.
Your best bet is have it towed to the dealer , you don't want to mess with the high pressure pump .
Pluse

First check for spark at the plugs, if ok check fuel pressure and flow, if flow is low change fuel filter , if pressure is low , check the pressure regulator at the fuel rail, if ok check voltage at the fuel pump if ok replace the pump. If you post again , please give more info as I don't know make or model and can only give general information

code p0642 refers to ECM-knock control defective or sensor reference voltage A circuit low or system voltage- malfunction===causes for ecm is ECM--- for voltage A wiring is short to positive --- for system voltage ---wiring--poor connection--battery---alternator
code p2014 refers to intake manifold air control actuator position sensor/ switch bank 1 circuit malfunction=== causes --wiring --intake manifold air control actuator position sensor/switch
code p0106 refers to manifold absolute pressure MAP sensor/barometric pressure sensor-range/performance problem===causes--intake /exhaust leak--wiring--MAP sensor---Baro sensor.
code p0089 refers to fuel pressure regulator --performance problem===causes--fuel pressure regulator--mechanical fault. I would suggest that you have the battery load tested and the alternator checked for correct output as it may be the common reason for the codes .P0089 will not be electrical as it being a mechanical fault then the regulator needs replacing

Could be a fuel pressure regulator or lost signal from crank sensor that gives inaccurate data.
The crank sensor is responsible for sending data to increase fuel pressure as a function of increased RPM. If the RPM reads low, then fuel pressure will be low.
Check fuel pressure.
Thinking that air pressure is affecting pressure regulator and compensating for a weak regulator diaphragm.
Would be interested in final fix of your problem.

The sensor and circuit would need to be tested.
The voltage signal back to the computer is below normal range.

Code 452 is for low voltage coming from the fuel tank pressure sensor. The computer uses the sensor in the tank to measure pressure when it is venting the tank to the canister.
The circuit would need to be tested.

Check your fuel pressure pressure regulator and check for full voltage going to the pump. If that checks out ok your fuel pump is probably weak, on the fuel strainer inside of the tank is clogged.
Good luck, i hope this helps.

Hi.

Check the fuel filter and fuel pressure regulator. They are part of the same assembly and are located on top of the fuel pump. To replace the regulator # Disconnect fuel supply line at the Filter/Regulator nipple and releas locking spring tab (2 in diag.) on the regulator, then turn counterclockwise and pull out. To test regulator use a gauge like this in fuel lines:Pump Pressure Tester.
Pressure in 2003 should be 58psi (48 in 2001 engines). Pressure will drop of about ten psi when you start engine.

There is also an automatic shut down relay ASR. If problem is the ASR the pressure will go down when the relay cuts off power to pump. Read voltages and see if the problem is electrical first before going for the regulator.

Check to see if fuel is getting to the filter. Maybe too much dirt in lines & plugged filter? If fuel at filter, put hose in place of filter JUST LONG enough to see if fuel is getting to fuel rail.