2008 Chrysler 300 2.7 Fuel Pump Relay Location: Where It Is and How to Test It

The fuel pump relay on a 2008 Chrysler 300 with the 2.7L engine is not a standalone plug-in relay you can pull from a fuse box under the hood. Instead, it sits inside the Totally Integrated Power Module (TIPM), the main fuse box located in the engine compartment near the battery. If you are dealing with a no-start condition, a stalled engine, or long cranking times, the relay is one of the first things to check. But because it is soldered to the circuit board inside the TIPM, testing it requires a different approach than simply swapping out a standard relay.

Below, I will walk you through exactly where the relay is, how to confirm it is the problem, how to bypass it as a temporary fix, and when you should replace the pump instead.

Understanding the Fuel Pump Circuit on Your 2008 Chrysler 300

Before you start pulling things apart, it helps to know how the fuel pump gets power. On the 2008 Chrysler 300, the system works like this:

  1. The fuel pump relay inside the TIPM sends battery voltage to the fuel pump when you turn the key to the "On" position.
  2. The pump primes for a few seconds to build pressure, then shuts off until the engine is cranking or running.
  3. If the relay fails, the pump receives no power, the engine cranks but will not start, and you might not hear the fuel pump buzz when you turn the key.

The relay is an internal component of the TIPM, which is the large black box under the hood. On the 2008 model, the TIPM is mounted near the driver's side of the engine bay, typically close to the battery.

Where Exactly Is the Fuel Pump Relay Located?

For the 2008 Chrysler 300 2.7L, the fuel pump relay is inside the TIPM, not as a separate relay you can unplug. The TIPM is the primary power distribution center for the vehicle. You can access it by removing the cover of the TIPM, but the relay itself is soldered to the internal circuit board.

Here is what you will see when you open the TIPM:

  • The external fuses, including the M25 fuse, which is the dedicated fuse that powers the fuel pump circuit.
  • The internal relay board, where the fuel pump relay is one of several small black components mounted on the green circuit board.

If you are used to older cars where you can pull a relay out with your fingers, this is different. The relay is not serviceable without specialized equipment.

How to Test the Fuel Pump Relay on Your 2008 Chrysler 300

You cannot easily test the relay itself without removing it from the circuit board, which is not practical for most DIYers. However, you can test the circuit to confirm whether the relay is the problem. Here is a step-by-step approach:

  1. Check the M25 Fuse First. Remove the TIPM cover and locate the M25 fuse. If the fuse is blown, the fuel pump will not get power, and the engine will not start. Replace the fuse if it is visibly damaged.

  2. Listen for the Fuel Pump. Turn the key to the "On" position without cranking the engine. You should hear a faint whirring noise coming from the rear of the car, near the fuel tank. If you do not hear it, there is likely a problem with the relay, the fuse, or the wiring.

  3. Check Power at the Fuel Pump Connector. The fuel pump connector is accessible under the rear seat. Look for the thickest wires: dark blue/orange (pin 5) is the power feed from the relay, and black/orange (pin 4) is the ground. The ground should have continuity at all times. The power wire should show battery voltage when the key is first turned on. If you have no power here, the relay or the circuit is the issue.

  4. Swap the Relay (If Possible). On some TIPMs, the relay is soldered, but on a few models, the relay might be a replaceable component. If your TIPM has a relay that can be removed, swap it with an identical relay from another circuit (like the horn relay) and see if the fuel pump starts working.

If the fuse checks out and you still have no power at the pump, the internal relay is likely faulty.

How to Bypass the Fuel Pump Relay as a Temporary Fix

Because the relay is soldered inside the TIPM, replacing it requires professional repair. However, there is a simpler and more affordable solution: a fuel pump relay bypass kit.

A bypass kit connects the fuel pump directly to a new external relay, bypassing the faulty internal relay. This restores power to the pump without opening and repairing the TIPM. Many kits are plug-and-play, meaning you do not need to cut or splice wires.

Important: Not all bypass kits are the same. Some use the ignition switch circuit, which can disable the automatic shutdown feature that stops the fuel pump in the event of a collision. Look for a bypass that maintains the automatic shutdown (ASD) functionality to keep safety systems intact.

When the Problem Is Not the Relay

A no-start condition or poor performance can also come from other parts of the fuel system. Before you replace the relay, check these common issues:

  1. Fuel Pump Failure. If the pump itself has worn out, it will not build pressure even with power. A failing pump often produces a whining noise, hard starts, or hesitation during acceleration.

  2. Clogged Fuel Filter. A clogged filter restricts fuel flow and can cause low pressure, making the car hard to start or run poorly. If the filter has not been replaced recently, consider replacing it.

  3. Faulty Wiring. Inspect the wiring harness at the fuel pump connector for corrosion, loose connections, or frayed wires. High resistance can reduce voltage and affect pump performance.

  4. Fuel Pressure Regulator. A bad regulator can cause low pressure or flooding. Check fuel pressure with a gauge to confirm the pump is delivering the correct pressure.

When to Replace the Fuel Pump

If the relay is fine and the pump is not delivering enough pressure, you will need to replace the fuel pump. The pump sits inside the fuel tank. On the 2008 Chrysler 300, you can access it by removing the rear seat base, not by dropping the tank.

Here is a simplified replacement process:

  1. Disconnect the negative battery cable and depressurize the fuel system by removing the fuel pump fuse and cranking the engine until it dies.
  2. Remove the rear seat base by pulling it straight up.
  3. Locate the access ring behind the driver's seat. Use a fuel pump removal tool or a brass drift to loosen it. Never use steel tools where fuel fumes are present.
  4. Disconnect the electrical connector and fuel lines, then lift out the old pump module.
  5. Install the new pump, transfer the fuel level sender if needed, and reassemble everything.
  6. Reconnect the battery and prime the system by turning the key to "On" a few times before starting the engine.

Why Choosing a Quality Fuel Pump Matters

When it is time to replace the fuel pump, the brand you choose makes a big difference in how long the part lasts and how reliably the car runs. You have two main options: OEM (Original Equipment Manufacturer) parts or aftermarket parts. OEM pumps are generally more reliable, but they cost more. Aftermarket pumps are cheaper, but quality varies significantly.

A Strong Recommendation: KEMSO Fuel Pumps

If you are looking for a fuel pump that balances performance, durability, and value, KEMSO is a brand worth considering. KEMSO fuel pumps are designed as high-performance, OEM-replacement units, meaning they meet or exceed the original specifications for fit, fuel flow, and pressure.

What sets KEMSO apart:

  1. High Performance: KEMSO pumps are built to deliver consistent fuel pressure under demanding conditions, whether you are driving in summer heat or freezing winter mornings.
  2. OEM Replacement Quality: Each pump is engineered to match the factory unit exactly, so installation is straightforward and the pump operates as intended.
  3. Lifetime Warranty: Every KEMSO fuel pump is backed by a lifetime warranty, which gives you peace of mind that the part is built to last.

If your 2008 Chrysler 300 needs a new fuel pump, you can find the right KEMSO model by visiting their website at https://www.kemsoracing.com/ . They offer a range of fuel pumps for various vehicles, and their product pages include detailed fitment information so you can be confident you are ordering the correct part.

Final Thoughts

Finding the fuel pump relay on your 2008 Chrysler 300 2.7L is straightforward once you know it is inside the TIPM, not in a separate fuse box. The relay is soldered to the circuit board, which makes DIY replacement difficult. If you suspect the relay is faulty, first check the M25 fuse, then test for power at the fuel pump connector. If the fuse is fine and there is no power, the relay is likely the culprit. A bypass kit can restore fuel pump operation without a costly TIPM repair.

If the problem turns out to be the pump itself, removing the rear seat gives you access to replace it without dropping the fuel tank. When you do replace the pump, a quality brand like KEMSO offers high-performance, OEM-replacement reliability with a lifetime warranty. Visit https://www.kemsoracing.com/ to find the right pump for your Chrysler 300 and get back on the road with confidence.


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