Where to Find Your 2019 GMC Sierra Fuel Pump Control Module Location (FPCM) and How to Access It

The fuel pump control module (FPCM) on your 2019 GMC Sierra 1500 is located behind the right rear (passenger side) wheel well liner. This vital component regulates the voltage and speed of your fuel pump. Knowing its precise location is essential if you suspect fuel delivery problems, need to test the circuit, or must replace a faulty module.

Why the FPCM Location Matters
The FPCM's job is crucial: it manages the electrical power sent to your Sierra's fuel pump. Unlike older systems running the pump at full voltage constantly, modern trucks use these modules for precise control. This improves efficiency, reduces pump wear, and minimizes noise. When the FPCM fails or its connections corrode, fuel delivery stops. Symptoms include a no-start condition, engine stalling, hesitation, poor acceleration, or intermittent loss of power. Accessing the module is often the first step in diagnosing these fuel system issues or performing a replacement. Mounting it near the fuel tank, yet slightly protected, helps shorten wiring runs while keeping it reasonably accessible compared to mounting it on the tank itself.

Essential Safety Precautions Before Accessing the FPCM
Dealing with any fuel system component requires caution. High fuel pressure, flammable vapors, and electrical risks are real concerns. Always do the following before starting work:

  1. Turn Off the Ignition: Ensure the key is removed or the start/stop button is off.
  2. Disconnect the Battery: Critical. Disconnect the negative (ground) cable from your Sierra's battery first, followed by the positive cable. This eliminates the risk of electrical sparks near the fuel system. Secure the cables away from the battery terminals.
  3. Depressurize the Fuel System (Recommended): Although you won't directly open a fuel line to access the FPCM, releasing system pressure is a wise precaution for overall safety if you need to disconnect any nearby components. Locate the Schrader valve (looks like a tire valve stem) on the fuel rail under the hood. Cover the valve with a rag and carefully depress the center pin using a small screwdriver or valve core tool. Be prepared for a spray of fuel. Wear eye protection.
  4. Allow Time for Cooling: Let the exhaust components near the rear wheel area cool down if the truck was recently running.
  5. No Smoking or Open Flames: Maintain a safe environment free of ignition sources.

Step-by-Step: Locating and Accessing the 2019 GMC Sierra FPCM
Accessing the FPCM requires removing the rear passenger-side wheel and wheel well liner. Here's the detailed process:

  1. Park Safely: Park your Sierra on a level, solid surface. Engage the parking brake firmly. Place wheel chocks securely against the front wheels to prevent rolling.
  2. Loosen Lug Nuts: Break the lug nuts on the rear passenger-side wheel loose using your lug wrench or impact gun, but do not remove them completely yet.
  3. Jack Up the Truck: Locate the proper jacking point near the rear passenger wheel according to your owner's manual. Lift the rear of the truck safely using a floor jack. Never rely solely on a scissor jack supplied with the vehicle. Ensure the truck is stable.
  4. Support with Jack Stands: This is non-negotiable. Place sturdy jack stands under the designated lift points on the frame. Carefully lower the truck onto the jack stands. Give the truck a firm shake to ensure stability. The floor jack can remain under the vehicle as an additional safety measure once the stands are positioned.
  5. Remove Lug Nuts and Wheel: Now fully remove the lug nuts and carefully pull the rear passenger wheel off. Place it aside safely.
  6. Remove the Wheel Well Liner: Look inside the wheel well. The inner surface is covered by a large plastic liner (fender liner) held in place by multiple plastic push-pin clips and screws. There are typically screws along the outer edge and some near the bottom.
  7. Remove the Push-Pin Clips: Use an interior trim removal tool or a small flathead screwdriver carefully to pry the center pin of each plastic push-pin clip up about ¼ inch. Then, you can pull the entire clip outwards. Collect the clips. Some screws might be hidden by grime.
  8. Remove Screws: Use an appropriate screwdriver or socket (usually 7mm or 8mm) to remove any screws securing the liner. Pay attention to screws along the rocker panel edge and the bottom edge near the frame.
  9. Pivot the Liner Out: Once all fasteners are removed, gently pull the liner outwards and downwards from the wheel well area. You do not need to fully remove it; just create enough space to work comfortably behind it. Tuck it aside.
  10. Identify the Fuel Pump Control Module: Look towards the outer side of the frame rail, positioned vertically behind the area where the wheel was. Mounted on a bracket attached to the frame (looks like a metal tab or small shelf), you will see a silver or black metallic box, roughly the size of a deck of cards or slightly larger. It has an electrical connector plugged into one end and often two large wires (positive and negative, typically orange/black) attached via studs and nuts on the other side.
  11. Visual Confirmation: The module housing usually has a part number sticker and the GM logo/part name. The part number should be visible (e.g., often starting with "135" like 13577459 for some models, though always check yours). Verify the orientation: Connectors towards the rear/front, wire terminals facing outwards/inwards relative to the frame. This is your 2019 GMC Sierra fuel pump control module location.

What the FPCM Looks Like & Connection Points
The module is a sealed electronic unit housed in a metal case for heat dissipation and protection. Key identifying features at the location:

  • Shape & Size: Rectangular metal box (aluminum or steel), approximately 3-4 inches long, 2-3 inches wide, and about 1 inch thick.
  • Mounting: Bolted to a dedicated bracket welded or bolted to the truck's frame rail. It has mounting holes or slots.
  • Electrical Connector: A weatherproof multi-pin connector (commonly 4-6 pins) plugs into one end. This carries the control signals and sensor inputs from the Powertrain Control Module (PCM). Disconnecting requires depressing a locking tab.
  • Power and Ground Terminals: Two studs or threaded posts protrude from the opposite end or side. Large gauge wires attach here:
    • Positive Supply (B+): Typically a fused wire coming directly from the battery or a main power distribution source, identifiable by an orange or orange/black color. Connected with a nut.
    • Ground (GND): A large black wire (or black with a white stripe) leading to a chassis ground point nearby. Also connected with a nut. This is the path back to the battery negative.
  • Output Harness: From the bottom or side of the FPCM, a thick wiring harness leads down and connects to the fuel pump assembly inside the fuel tank. This harness carries the high-current power sent to the pump motor itself.

Common Challenges & Tips When Accessing the FPCM
Be prepared for:

  • Rust and Corrosion: This area is exposed to road salt, dirt, and water. Fasteners and the FPCM case/terminals are prone to rust. Penetrating oil (like PB Blaster) applied beforehand can help loosen stuck bolts and nuts. Be prepared to use force on rusty clips or fasteners. Wire brush terminals carefully.
  • Tight Working Space: Even with the wheel off, maneuvering tools behind the liner can be awkward. Patience and the right tools (small wrenches/sockets, wobble extensions) help. Clearance lights or headlamps provide essential illumination.
  • Dirt and Grime: Expect caked-on dirt and grease. Cleaning the immediate area with a brush helps visibility and prevents debris from falling onto electrical contacts during connector removal.
  • Seized Mounting Bolts/Nuts: Bolts holding the FPCM bracket or nuts securing the power wires can corrode badly. If necessary, small sockets or wrenches (e.g., 7mm, 8mm, 10mm) combined with penetrating oil are needed. Apply firm pressure but avoid rounding off the fasteners.
  • Difficulty Identifying Connector Locking Tabs: Dirt and age can make tabs hard to see and operate. Inspect the connector closely and clean it first if possible. Use a pick tool to gently pry the tab.

FPCM Issues and Repair Options
If you've found the module but suspect it's the culprit:

  • Diagnosing Failure: Symptoms like crank/no-start, stalling, loss of power, or loud buzzing noises from the rear often point to FPCM or pump issues. Diagnostic trouble codes (DTCs) like P0230 (Fuel Pump Primary Circuit), P0627 (Fuel Pump "A" Control Circuit/Open), P069E (Fuel Pump Control Module Requested MIL Illumination), or P2635 (Fuel Pump "A" Low Flow / Performance) strongly implicate the FPCM circuit. Checking for power and ground at the module input and output pins requires a multimeter.
  • Replacement: If testing confirms a faulty module, replacement is necessary. FPCMs are typically not repairable internally. Use the original part number found on the sticker. While aftermarket modules exist, GM Genuine or ACDelco Professional replacements are recommended for best compatibility and longevity. Ensure the part matches your Sierra's engine and model year.
  • Bypass Kits (Use with Caution): Bypass kits, which directly power the pump at full voltage, are sometimes discussed online. We strongly advise against permanent bypasses. While they might temporarily get the vehicle running, constantly running the pump at full speed leads to premature pump failure, ignores potential underlying wiring faults, disables sophisticated fuel control strategies, and poses serious safety risks related to unregulated fuel pressure or potential overheating. They are not a reliable fix.
  • Electrical Repairs: Often, problems stem from corroded or damaged wires at the connector or the power/ground terminals, not the module itself. Carefully inspect the wiring harness for damage (chafing, rodent chewing), corrosion, and loose connections. Clean terminal posts and connectors thoroughly before condemning the module. Repair damaged wiring properly using solder and heat shrink tubing or high-quality connectors.

When to Call a Professional Mechanic
Accessing the FPCM location is a moderately difficult DIY job involving safety-critical lifts, confined spaces, and high-current electrical components.

Consider seeking professional help if:

  • You are uncomfortable lifting the vehicle safely.
  • You lack the necessary tools or experience with automotive electrical systems.
  • Rust has severely seized critical bolts or fasteners.
  • Diagnostic testing reveals complex electrical issues beyond a simple module swap.
  • The problem persists after module replacement, indicating deeper wiring or PCM issues.
  • You are at all unsure about any step in the process.

A certified technician has the lifts, diagnostic scan tools (like a Tech 2 or MDI), oscilloscopes for signal verification, repair information, and experience to diagnose and resolve FPCM or fuel system problems efficiently and safely. Incorrect diagnosis or repairs can be costly and dangerous.

Finding Parts for Your FPCM Replacement
When sourcing a replacement:

  • GM Genuine Parts: Order using your Sierra's VIN through a dealership parts counter for absolute compatibility.
  • ACDelco Professional: GM's OE supplier brand, often available through auto parts stores or online retailers.
  • Reputable Aftermarket Brands: Ensure they specifically list compatibility with the 2019 Sierra. Always cross-reference your original module's part number.
  • Retailers: Auto parts chains (AutoZone, O'Reilly, NAPA, Advance Auto Parts), dealerships, and major online retailers (Amazon, RockAuto) typically stock or can order FPCMs. Expect to pay for the quality and precision engineering required for this component.

Conclusion
Finding the 2019 GMC Sierra fuel pump control module location – behind the passenger-side rear wheel well – is straightforward once you know where to look, but accessing it requires lifting the truck safely and removing the inner liner. Remember the critical importance of disconnecting the battery first and working carefully near the fuel system. While replacing the FPCM itself is usually simple plug-and-play if you've accessed it, proper diagnosis beforehand is crucial to avoid unnecessary expense. If the symptoms or any step in the process causes concern, enlisting the expertise of a qualified mechanic is the wisest and safest course of action to get your Sierra back on the road reliably. Knowing this location empowers you to understand your truck's fuel system better, whether you tackle the job yourself or oversee the repair professionally.

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