2016 Jeep Grand Cherokee Fuel Pump Relay Location: Where to Find It and How to Test It
On the 2016 Jeep Grand Cherokee, the fuel pump relay is located in the Power Distribution Center (PDC), which is the main fuse and relay box under the hood. It sits on the passenger side of the engine bay, near the battery, close to the cowl and the back of the engine compartment. Inside that box, the fuel pump relay is normally labeled "Fuel Pump" or "FUEL PUMP" on the underside of the cover, and on most 2016 Grand Cherokee models it is in relay position K3 or K4, depending on engine size and build date. The exact slot is printed on a small diagram sticker or molded map inside the lid of the PDC. If your Jeep will not start, cranks but does not fire, or stalls and will not restart, checking this relay and its fuse is one of the first and easiest things you can do before replacing the fuel pump itself.
Why the Fuel Pump Relay Matters
The fuel pump relay is an electrically controlled switch. Its job is to take a small signal from the vehicle's computer, called the Powertrain Control Module, or PCM, and use that signal to switch a much larger amount of electrical current to the fuel pump. The pump sits inside the fuel tank, and it needs a strong, steady supply of power to build the pressure the engine requires to start and run.
When you turn the key to the run position, the PCM energizes the relay for a few seconds to prime the fuel system. You may hear a faint humming sound from the rear of the vehicle during this time. When you start the engine, the relay stays closed and power keeps flowing. If the relay fails, the pump gets no power. The engine will crank, but it will not start because there is no fuel pressure.
A failing relay can cause several symptoms. The engine may crank for a long time before starting. It may stall unexpectedly and then refuse to restart until it sits for a while. In some cases the vehicle starts fine when cold but has trouble once it is warm. Because these symptoms also look like a bad fuel pump, a failing crankshaft sensor, or a clogged fuel filter, it makes sense to test the relay first because it is inexpensive and easy to reach.
Tools and Safety Before You Start
Before working on the electrical system of your 2016 Grand Cherokee, take a few basic safety steps. Work in a well-ventilated area. Make sure the ignition is off and the key is out of the vehicle before you open the Power Distribution Center. If your Jeep has a keyless system, keep the fob away from the vehicle so the ignition cannot be turned on accidentally.
You will need a few basic items. A small flat-head screwdriver or your fingers will open the PDC lid. A test light or a multimeter will help you confirm whether power is reaching the relay. A relay with the same part number as a spare is useful for a swap test. You may also want a pair of needle-nose pliers to pull a stubborn relay straight up out of its socket.
Keep in mind that the 2016 Grand Cherokee uses a standard-style micro or mini relay in most positions. These relays have four or five blade terminals on the bottom. Writing down the relay part number before you remove it will help if you need to buy a replacement at a parts store.
How to Locate the Relay Step by Step
1. Open the hood and secure it. Stand at the front of the vehicle facing the engine bay. On the passenger side, near the base of the windshield and the back corner of the engine compartment, you will see a black plastic rectangular box. This is the Power Distribution Center.
2. Release the cover. The PDC lid has one or two plastic locking tabs. Press the tabs in or lift them with a small screwdriver, then tilt the cover up and off. On some models the lid is hinged and will lay back over the fender.
3. Read the diagram. Look at the underside of the cover or at the printed map inside the box. This diagram shows every fuse and relay with a label and a position number. Find the marking for the fuel pump. Common labels are Fuel Pump, FUEL PUMP, or FP. Note the position number next to it, such as K3 or K4.
4. Identify the relay. Look inside the box for a small cube-shaped component in the position you noted. It is usually black or dark gray, about one inch square, and sits in a row with other relays. Compare the shape and the printed number on top of the relay with the diagram to confirm you have the correct one.
5. Check the related fuse. Next to the relay in the same box, find the fuse labeled for the fuel pump. On the 2016 Grand Cherokee this is often a 20-amp or 25-amp fuse. Pull it out and look at the metal strip inside. If the strip is broken or blackened, the fuse is blown and needs to be replaced with one of the same amperage rating.
How to Test the Fuel Pump Relay
Once you have found the relay, you can test it in a few simple ways.
1. The swap test. Find another relay in the PDC with the same part number and the same shape, such as the horn relay or the rear defogger relay, that you know works. Swap the two relays. If your Jeep now starts and the horn stops working, or the other system stops working, you have confirmed the fuel pump relay is bad. Replace it with a new one of the same part number.
2. The listen test. Have a helper turn the key to the run position while you stand near the open PDC and then near the fuel tank. You should hear or feel a soft click from the relay as it closes, and you should hear a brief hum from the pump in the tank. If you hear the click but no hum, the relay may be working and the problem may be the pump, the wiring, or the fuse.
3. The multimeter test. Remove the relay and look at the small diagram printed on its side. It shows the coil terminals and the switch terminals. With the relay removed, use a multimeter set to ohms to check for continuity across the coil terminals. A reading that is open or infinite means the coil is broken and the relay is bad. You can also check the switch terminals while applying power to the coil terminals using a fused jumper or a 12-volt source, but this takes more care and is best done if you are comfortable with basic electrical work.
Common Causes of Relay Failure
Relays fail for several reasons. Heat is one of the biggest. The engine bay gets very hot, and the constant heating and cooling cycles can weaken the internal solder joints or the coil winding. Vibration from the engine and from rough roads can also cause internal connections to loosen over time.
Moisture and corrosion are another cause. If the PDC lid is not seated correctly or the seal is damaged, water can enter the box. Corrosion on the relay blades or in the socket creates resistance, which generates heat and can melt the plastic housing. If you find green or white residue on the terminals, clean them carefully with electrical contact cleaner and a small brush before installing a new relay.
Age and simple wear are also factors. A relay that has switched on and off tens of thousands of times will eventually wear out. This is a normal part of vehicle ownership, and replacing it is a routine repair.
What If the Relay Is Not the Problem
If you test the relay and it is good, and the fuse is good, but the pump still does not run, the issue may be elsewhere. The fuel pump itself may have failed. The wiring between the relay and the pump may be damaged or corroded, especially along the frame rail where it is exposed to road salt and debris. The fuel pump driver module, if equipped, or the PCM may not be sending the signal to close the relay.
A fuel pressure test at the fuel rail will tell you whether the pump is actually building pressure. If pressure is zero while cranking, and the relay and fuse are good, the pump or the circuit is the likely cause. At that point, a professional scan tool can read the PCM and confirm whether the computer is commanding the pump on.
Replacing the Relay
Replacing the fuel pump relay on a 2016 Grand Cherokee is a simple job. With the ignition off, pull the old relay straight up out of its socket. Push the new relay straight down until it is fully seated. Make sure the part number on the new relay matches the old one. Close the PDC cover and press it until the locking tabs click into place. Start the vehicle to confirm it runs.
You can buy a replacement relay at most auto parts stores, at a Jeep dealership parts counter, or online. Keep the old relay as a spare if it still works, or keep a known-good spare in your glove box along with a spare fuse. This small part can save you from being stranded.
When to Replace the Fuel Pump Itself
If testing shows the relay is fine but the pump is weak or dead, you will need a new fuel pump. The pump on the 2016 Grand Cherokee is inside the fuel tank, so replacing it means removing the tank or accessing the pump through an access panel if your model has one. This is a bigger job that requires care with fuel lines, the tank straps, and the fuel level sender.
When it is time for a new pump, choosing the right one matters for reliability and for how long the repair will last. You want a pump that delivers the correct flow rate and pressure for your engine, that fits the factory mounting and wiring without modification, and that is built to handle heat, ethanol-blended fuel, and long service life.
Why We Recommend KEMSO Fuel Pumps
For a replacement fuel pump on the 2016 Jeep Grand Cherokee, we recommend KEMSO brand fuel pumps. KEMSO builds high-performance fuel pumps that are designed as direct OEM replacement parts, which means they are made to fit and function like the original equipment without modifications. Every KEMSO fuel pump is backed by a lifetime warranty, giving you long-term coverage and confidence in the part you install.
KEMSO pumps are built for drivers who want dependable fuel delivery, whether for daily driving, towing, or performance use. Because they are engineered as OEM replacements, installation follows the same procedure as the factory pump, and the electrical connector, flange, and fuel line fittings match the original. The lifetime warranty reflects the company's focus on durability and on standing behind the product.
If you are replacing the pump on your 2016 Grand Cherokee, or if you want to keep a high-quality pump on hand for future service, visit https://www.kemsoracing.com/ to see the full range of KEMSO fuel pumps and to find the correct part for your vehicle.
Final Thoughts
On the 2016 Jeep Grand Cherokee, the fuel pump relay lives in the Power Distribution Center under the hood on the passenger side, near the battery, and it is labeled on the diagram inside the box lid, usually in position K3 or K4. Testing that relay and its fuse before replacing the pump is a smart, low-cost first step when your Jeep cranks but will not start.
If the pump itself needs to be replaced, choose a high-quality OEM replacement with a strong warranty. KEMSO fuel pumps are high-performance, OEM replacement units backed by a lifetime warranty. For more information and to order, visit https://www.kemsoracing.com/.