A 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
The service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones). click here to download the app (for users in the US for now) and get all the help you need. Good luck!
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
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.
Fuel Pump Flow Control Module (Gas except LU3/LMG/LY6/LC9)
Mounted to the rear frame, near the spare tire mount
Wheels/Vehicle Underbody Component Views
Component Connector End Views
Fuel Pump Relay - Secondary (Gas with LY6)
On the fuse block - underhood bracket
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
The engine control module (ECM) sends the fuel enable signal to the fuel pump control module (FPCM). The control module monitors the voltage on the fuel pump relay control circuit. If the control module detects an incorrect voltage on the fuel pump relay control circuit, a fuel pump relay control DTC sets.
The control module monitors the voltage on the fuel pump relay control circuit. If the control module detects an incorrect voltage on the fuel pump relay control circuit, a fuel pump relay control DTC sets.
DTC P0231: Fuel Pump Control Circuit Low Voltage
DTC P0232: Fuel Pump Control Circuit High Voltage
DTC P023F: Fuel Pump Control Circuit
DTC P025A: Fuel Pump Control Module Enable Circuit
Your best bet , take it to a qualified repair shop , dealer .
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 .
If the fuel pump/s continue to run with key on, suspect a relay issue. The relay is grounded by the vehicles computer. If the computer supplies a constant ground, the relay will continue to stay closed and power the fuel pumps constantly. If the the ground wire that comes from the computer to the relay is shorted/grounded, the relay will stay energized as well. As for the no start, are the injectors getting a power and ground supply? The ground side of the injector is controlled by the computer as well. Is the vehicle getting spark at the coil/plug? Have you scanned the computer for any trouble codes?
check for a problem fuel pressure regulator
most are wired to the ECM which is connected to the relay for the pump
it works like this
with low / no fuel pressure the regulator completes a circuit to the ECM
that signal is then sent to a relay to start the pump
when full pressure is reached , the regulator signals the ECM and the relay is turned off hence the pump is not continually running when pressure is not required
This relay is located behind the dashboard's lower cover. It consists of two individual relays. One is energized whenever the ignition is ON , thus supplying battery voltage to the Powertrain Control Module (PCM). This relay also supplies voltage to the fuel injectors, and power to the second relay. The second relay is energized for two seconds, when the engine is turned ON , to power the fuel pump.
See Figure 1
Fig. Fig. 1: Schematic of the PGM-FI relay Testing
If the engine starts and continues to run, the PGM-FI relay is working and does not need to be replaced.
See Figure 2
Fig. Fig. 2: PGM-FI relay terminal numbers
Remove the relay.
Apply battery voltage to the number three terminal.
Ground the number two terminal.
Check for continuity between terminals five and two.
If continuity is detected, proceed to the step 7.
If there is no continuity, replace the relay.
Connect the number four terminal to the positive side of the battery.
Ground the number two terminal of the relay.
Check for continuity between the number five terminal and the number two terminal of the relay.
If there is continuity, the relay checks out "OK". If the fuel pump still does not work, test the harness.
If there is no continuity, replace the relay and retest.
many fuel pumps get there power from the relay that is energized by the ECM
there is a pressure regulator in the system that will report to the ECM to switch on the fuel pump when the pressure falls
if you have no power to the relay , it could be because the pressure in the fuel system is above cut in pressure or that pressure regulator is not passing the current to the ECM
Dark green provides power to fuel pump relay from the ECU. Orange wire at fuel pump relay is power at all time and is provide from the ECM/Bat Fuse at fuse block (Left side of dash). It also connects to the fuel pump oil pressure switch. The grey wire at relay provides power to the fuel pump and fuel pum oil pressure switch. The red plug thats tape to harness from relay/fuse center is the prime connector..