Low voltage to fuel ump module

if sounds like out of time test and check that it didnt ump a tooth

These trucks are well known for their fuel pump control modules going bad. They are made of aluminum and are bolted to the left rear inner frame rail. The aluminum rots away and allows water to get inside. The water quickly destroys the circuit board. Honestly I don't know what you have tested or replaced so far. Why do you want to test the PCM? To shorten the amount of corresponding E-mails please write back and explain what you have done so far and exactly what diagnostic information you are looking for.

Is the security light lit on the instrument cluster ? It's not a fusible link problem .Get 2.4 volts between 86& 87 You may see some voltage there , not battery voltage . Pin 30 should have battery voltage , this is supply voltage for the S terminal at the starter solenoid . Pin 86 is control side of the relay , ECM supply's a ground on pin 85 . Do you know how the starting system works on this vehicle ? The ignition switch is a low voltage input to the BCM - body control module , when the BCM see's crank input from the ignition switch it sends a message over the GMLAN serial data network to the ECM for crank .
Circuit Description
For ignition switch power modes refer to Body Control System Description and Operation. Once the ignition is placed in the Run/Crank position, the control circuit of the Run/Crank relay is grounded by the body control module (BCM). With the Run/Crank relay switch closed, battery positive voltage flows through it and on to the park/neutral position (PNP) switch. With the PNP switch in either the Park or Neutral position, battery positive voltage will flow to the starter relay coil supply voltage input terminal of the engine control module (ECM) and the coil side of the starter relay. Placing the ignition in the START position sends a message to the engine control module ECM requesting engine start. If the ECM has determined that the transmission is in Park or Neutral and theft is not active, it will ground the control circuit of the starter relay. Battery positive voltage will then flow through the switch side of the starter relay to the S terminal of the starter solenoid, cranking the engine.
Your best bet , with all the parts you changed needlessly an not having a clue as to how this system works , do yourself a favor an take it to a qualified repair shop . You need to have a factory or some other type of professional scan tool hooked up an do a full vehicle scan .With all the modules on the vehicle , all's it takes is one bad module to bring down the data network an messages from module to module won't happen .
Power Mode Master
This vehicles body control module (BCM) functions as the power mode master (PMM). Refer to Power Mode Description and Operation for a complete description of power mode functions.
Serial Data Gateway
The body control module (BCM) in this vehicle functions as a translator between the High and Low speed GMLAN busses. The 2 communication protocols use the BCM to translate communicated serial data messages between the control modules over the 2 serial data busses.

Circuit Description
The communication among control modules is performed through the GMLAN high speed serial data circuit and the GMLAN low speed serial data circuit. The modules that need real time communication are attached to the high speed GMLAN network. The body control module (BCM) is the gateway between the networks. The purpose of the gateway is to translate serial data messages between the GMLAN high speed buss and the GMLAN low speed buss. The gateway will interact with each network according to that network's transmission protocol. Refer to Body Control System Description and Operation for more information about the gateway.


https://www.youtube.com/watch?v=bu2NUqRMZ4g&t=190s

Did you ground out the coil secondary while cranking? If not there's a very good chance you fried the ignition module. It's mounted in the distributor and some parts stores have a module tester so get it checked also check fuses. I hope this helps, Take care. Merry Christmas

Your fuel pressure is really low.

Ran a hot wire to what fuel pump or the control module ? Which of these is yours ?
Figure 9: Fuel Controls - Fuel Pump Controls (LY6)
Figure 10: Fuel Pump Flow Control Module (Except LY6) Does yours have fuel pump flow control module under the vehicle Fuel Pump Flow Control Module (except LY6)
Mounted to the left side of the frame assembly below the driver seat ?
Fuel Pump Flow Control Module (FPCM) - LMF
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 25 KHZ PWM signal to the fuel pump, and pump speed is changed by varying the duty cycle of this signal. Maximum current supplied to the fuel pump is 15 amps. A liquid fuel pressure sensor provides fuel pressure feedback to the FPCM.
Electronic Returnless Fuel System (ERFS) - LMF
The electronic returnless fuel system is a microprocessor controlled fuel delivery system which transports fuel from the tank to the fuel rails. It functions as an electronic replacement for a traditional, mechanical fuel pressure regulator. A pressure vent valve within the fuel tank provides an added measure of fuel pump flow control module (FPCM). Desired fuel pressure is commanded by the engine control module (ECM), and transmitted to the FPCM via a GMLAN serial data message. A liquid fuel pressure sensor provides the feedback the FPCM requires for Closed Loop fuel pressure control.
If your vehicle has this system check it for DTC'S - diagnostic trouble codes . Will take guess work out of it .
DTC P0191: Fuel Rail Pressure (FRP) Sensor Performance
DTC P0192: Fuel Rail Pressure (FRP) Sensor Circuit Low Voltage
DTC P0193: Fuel Rail Pressure (FRP) Sensor Circuit High Voltage
DTC P0230: Fuel Pump Relay Control Circuit
DTC P0231: Fuel Pump Control Circuit Low Voltage
DTC P0232: Fuel Pump Control Circuit High Voltage
DTC P023F: Fuel Pump Control Circuit
The engine control module (ECM) supplies voltage to the fuel pump flow control module (FPCM) when the ECM detects that the ignition is on. The voltage from the ECM to the FPCM remains active for 2 seconds, unless the engine is in crank or run. While this voltage is being received, the FPCM supplies a varying voltage to the fuel tank pump module in order to maintain the desired fuel rail pressure.
DTC P025A: Fuel Pump Control Module Enable Circuit .
Ford Electronic Returnless Fuel System Diagnosis Part 1 this for ford but the GM system works the same . You'll need a wiring diagram so you know what wires are what . Free wiring diagrams http://www.bbbind.com/free_tsb.html

What about your ignition module? I can't tell if you just replaced coils or ignition module included? Also, before buying anything, check voltage and ground for ignition module. Pink wire is voltage, black wire is ground.

The crank sensor sends ac signal to ignition module, the module converts signal to dc, something the computer can handle, then sends rpm signal to computer.

DTC P025A: Fuel Pump Control Module Enable Circuit
Your problem is the fuel pump control module , do you know what this is !
Circuit/System Description
The engine control module (ECM) supplies voltage to the fuel pump flow control module (FPCM) when the ECM detects that the ignition is on. The voltage from the ECM to the FPCM remains active for 2 seconds, unless the engine is in crank or run. While this voltage is being received, the FPCM supplies a varying voltage to the fuel tank pump module in order to maintain the desired fuel rail pressure.
Electronic Returnless Fuel System (ERFS) - LMF
The electronic returnless fuel system is a microprocessor controlled fuel delivery system which transports fuel from the tank to the fuel rails. It functions as an electronic replacement for a traditional, mechanical fuel pressure regulator. A pressure vent valve within the fuel tank provides an added measure of fuel pump flow control module (FPCM). Desired fuel pressure is commanded by the engine control module (ECM), and transmitted to the FPCM via a GMLAN serial data message. A liquid fuel pressure sensor provides the feedback the FPCM requires for Closed Loop fuel pressure control.
Fuel Pump Flow Control Module (except LY6)
Mounted to the left side of the frame assembly below the driver seat
DTC P0452: Fuel Tank Pressure (FTP) Sensor Circuit Low Voltage


What negative wire gets hot ?
What
your pro

first see if you can hear the fuel pump in the tank, then if you can then check for spark at any spark plug also note if cranks slow like low battery voltage as this can and will cause a feed back of voltage to the distributor control module and short it out, if no spark replace the distributor

just a thought pull a coulpe of spark plugs see if there flooded also if you can scan the veh look at tps voltage now and look for cranking rpms should be around 240 rpms