2006 Audi A4 Fuel Pump Relay Location: The Complete Guide for Owners

The fuel pump relay on a 2006 Audi A4 is located in the relay carrier under the dashboard on the driver's side, behind the side dash panel cover. For most 2006 A4 models, including both the 2.0T and 3.2L variants, this relay sits in a row of relays that you can access by removing a plastic cover on the left side of the dashboard . However, depending on your engine code and build date, the exact position can vary, so you need to verify what you are looking at before pulling parts. If you hear no priming noise when you turn the key to the ON position, the fuel pump relay is one of the first items to inspect, but as we will cover below, cold weather and other components can also cause the same symptom .

This guide walks you through everything you need to know: where exactly to find the relay, how different engine codes affect its position, how to test it, and what steps to take if the relay is not the real problem. The 2006 Audi A4 (B7 generation) has been on the road for nearly two decades now, and fuel system issues are among the most common complaints from owners. Knowing where to look and what to check can save you both time and money at the shop.

Understanding the B7 Platform and Fuel System Basics

The 2006 Audi A4 belongs to the B7 generation, which ran from 2004 through 2008 in the U.S. market. This generation came with a variety of engines, including the 2.0T four-cylinder and the 3.2L V6. The fuel system on these cars uses an electric fuel pump located inside the fuel tank. When you turn the ignition key to the ON position, the fuel pump relay activates and sends power to the pump for about two seconds, building up pressure in the fuel lines so the engine can start quickly .

That brief hum you hear when you turn the key is the pump priming. If you do not hear it, the relay, the pump itself, or the wiring between them may be the problem. On 2006 models, the fuel pump relay is often marked with a number or a part number that helps you identify it.

The earlier Audi A4 B6 generation (2002-2004) had the fuel pump relay in a similar location, but the B7 uses a slightly different relay layout. Owners have reported confusion because the relay location is not always documented clearly in the owner's manual, and some online sources point to different spots .

Where the 2006 Audi A4 Fuel Pump Relay Is Located

For the majority of 2006 Audi A4 models, the fuel pump relay sits in the relay panel behind the driver's side dash panel. To access it, open the driver's door and look at the side of the dashboard. You will see a plastic cover that you can pry off with a trim tool or a flathead screwdriver. Behind this cover are several relays and fuses .

According to one owner who documented the process for a 2006 A4 2.0T FWD FSI, the fuel pump relay is under the dash, but you may need to remove the wiper arms and the plastic cowl cover to reach the relay carrier in some configurations . That said, the passenger compartment fuse box on the driver's side is the primary location for the fuel pump relay on most B7 models .

Here is the general layout you will see behind that dash cover:

  1. Relay R1 is the fuel pump relay for petrol models, positioned at the top of the relay carrier .
  2. Fuse number 28 (S228) is the fuel pump fuse, located in the same fuse box .

On some models, there are two identical relays in that area. Owners have reported that the "most forward" relay of the two is the one related to the fuel pump, though the other relay may serve a different function .

Engine Code Variations and Relay Position Differences

The 2006 A4 came with several engine options, and the relay location can vary depending on the engine code. If you have a model with the 3.2L V6 (engine code BHF), the relay positions differ from the 2.0T models.

For the 4.2L V8 models (engine code BHF), which were available in some markets, the relay carrier is located in the electronics box in the plenum chamber, under the wiper cowl . That is a different location from the dash-mounted relays on the four-cylinder cars. The relay carrier in the plenum chamber contains:

  1. Motronic current supply relay (J271)
  2. Secondary air pump relay (J299)
  3. Automatic gearbox relay (J60)
  4. Continued coolant circulation relay (J151)

If you own a 2.0T model (engine code BPY or similar), the fuel pump relay is more likely to be behind the dash panel on the driver's side . The 2.0T fuel pump relay is commonly listed as relay R1 in the under-dash relay box .

For the 3.2L V6 models (engine codes AUK, BKH), the fuel pump relay may also be located in the relay carrier under the dash, but you should verify your specific engine code from the sticker in your owner's manual or under the hood.

How to Access the Fuel Pump Relay Step by Step

Accessing the fuel pump relay on a 2006 Audi A4 is a straightforward job that most DIYers can handle with basic hand tools. Here are the steps you should follow:

Step 1: Gather the necessary tools. You will need a trim removal tool or a flathead screwdriver, a flashlight, and possibly a small mirror to see behind the dash.

Step 2: Open the driver's door and locate the side dash cover. Look at the left side of the dashboard (the end panel facing the door). Push gently on the cover or use a trim tool to pry it off. It is held in place by clips, so work carefully to avoid breaking them .

Step 3: Identify the relay carrier. Once the cover is off, you will see a fuse/relay panel with several small relays and fuses. The fuel pump relay is often labeled on the panel cover, but on many 2006 models, the labeling is absent or faded.

Step 4: Locate relay R1. According to fuse box diagrams for the 2006 A4, the fuel pump relay is positioned at the R1 slot in the under-dash relay box . If you have a 2.0T model, this is your target.

Step 5: Remove and inspect the relay. Before pulling the relay out, note its position and orientation. Pull it straight out. You can test it with a multimeter or simply swap it with an identical relay from another slot (like the horn relay) to see if the fuel pump starts working .

What If You Cannot Reach the Relay Through the Dash?

Some 2006 A4 owners have found that the relay is not accessible from the interior without more extensive disassembly. In these cases, you may need to remove the wiper arms and the plastic cowl cover at the base of the windshield to reach the electronics box .

The wiper arms are held on by nuts, and you will need a wiper puller tool to remove them. One owner noted that using a battery terminal puller from an auto parts store worked, though it broke after removing the first arm . Once the cowl is off, you can see the ECU and the relay carrier beneath it.

If you have a 4.2L V8 model, the engine electronics box in the plenum chamber is your primary relay location . Open the hood, remove the plastic cover over the wiper area, and look for the relay carrier labeled with the relays mentioned earlier.

Testing the Fuel Pump Relay

Once you have located the relay, you should test it before replacing it. A bad relay will not click when you turn the ignition on, and the fuel pump will not prime. Here is a method for testing the relay that works on most B7 models:

  1. Remove the fuel pump fuse (number 28) from the fuse box on the left side of the instrument panel .
  2. Connect an LED voltage tester between a good ground and one of the two fuse contacts.
  3. Have someone turn the ignition key to the ON position while you watch the tester.
  4. Listen for the relay to click. If you hear the click and the LED lights up, the relay is working.
  5. If the LED does not light, move the tester to the other fuse contact and repeat .

You can also swap the fuel pump relay with another identical relay from the same panel. On many 2006 A4s, there are two identical 614-style relays in the relay carrier. If the fuel pump primes after swapping, your original relay is faulty .

Common Symptoms of a Faulty Fuel Pump Relay

Knowing the symptoms can help you diagnose the issue before you even open the tool box. The most obvious sign is the absence of the priming noise when you turn the key to the ON position. Other symptoms include:

  1. The engine cranks but will not start. This is the most common complaint. The pump is not delivering fuel because the relay is not sending power to it .
  2. The engine stalls while driving. If the relay fails intermittently, you may lose engine power while on the road.
  3. No noise from the fuel tank area. When you turn the ignition on, you should hear a soft whirring sound from the rear of the vehicle for about two seconds. If you do not, suspect the relay or the pump .

On some 2006 models, the relay may become less reliable in cold weather. One owner in a Canadian climate reported that the fuel pump would not prime at all when temperatures dropped below -10°C. After extensive testing, the cause turned out not to be the relay but a frozen fuel pump module in the trunk. Warming the area around the pump with a hair dryer restored function .

The Cold Weather Issue: When the Relay Is Not the Problem

Cold weather can expose other weaknesses in the fuel system. Many owners in northern states and Canada have reported that their 2006 A4 will not prime or start in freezing temperatures. The fuel pump relay itself is usually fine in these cases. Instead, the problem often lies in the low-pressure fuel pump module located in the trunk, not under the rear seat .

The fuel pump on the B7 A4 is accessible through an access panel in the trunk floor, behind the rear seat. If you lift the trunk carpet and remove the floor covering, you will see a circular cover that provides access to the fuel pump flange . The small module attached to this cover is the pump controller, and it can freeze in very cold conditions .

If you experience this issue, try these steps:

  1. Use a hair dryer to warm the pump module before attempting to start the car.
  2. Plug in a block heater if you have one, as this helps warm the entire fuel system.
  3. Keep the fuel tank at least half full during winter to reduce condensation and freezing.

The fuel pump itself on the 2006 A4 is located inside the fuel tank. To replace it, you will need to relieve fuel system pressure, disconnect the battery, and remove the access cover in the trunk .

Fuse and Relay Overview for the 2006 A4

To help you understand the layout, here is a quick overview of the fuse and relay positions related to the fuel system on the 2006 A4:

Passenger Compartment Fuse Box (Driver's Side Dash):

  • Fuse 28 (S228) – Fuel pump fuse, rated at 20A
  • Relay R1 – Fuel pump relay for petrol models

Under-Dash Relay Box:

  • R2, R3, R4, R6 – Various other relays (blower motor, wipers, etc.)

Engine Compartment Electronics Box (for V8 models):

  • Motronic current supply relay (J271)
  • Secondary air pump relay (J299)
  • Automatic gearbox relay (J60)

If your car is a 2006 A4 with the BHF engine code, the fuel pump relay may actually be in the plenum chamber rather than under the dashboard. Always verify with a repair manual or a trusted online source specific to your engine code.

When to Replace the Relay and What Part to Buy

If your relay fails the test, you should replace it. The original relay part number for the 2006 A4 is 8E0-951-253, which has been superseded by 4H0-951-253 (often labeled as relay number 644) .

When purchasing a replacement relay, look for a genuine Audi part or a high-quality aftermarket equivalent. Relays are relatively inexpensive, and swapping them takes only a few minutes. You can find them at:

  • Audi dealership parts departments
  • Online OEM parts retailers such as FCP Euro or ECS Tuning
  • Auto parts stores like AutoZone or O'Reilly, which carry universal relays with the same pin configuration

Be careful when buying cheap no-name relays online, as they may not handle the current draw of the fuel pump reliably. A relay that fails again shortly after installation will leave you stranded.

How to Replace the Fuel Pump If the Relay Is Fine

If you have confirmed that the relay is working but you still do not hear the pump prime, the pump itself may be defective. Replacing the fuel pump on the 2006 A4 is a moderately involved job, but it is doable in a home garage with the right tools.

First, relieve fuel pressure by removing the fuel pump relay and letting the engine idle until it stalls . Then, disconnect the negative battery cable. Open the trunk and remove the carpet and trunk floor covering to access the fuel tank access panel .

You will need the following tools:

  • Audi tool #3307 to remove the fuel pump locking ring
  • Audi tool #3217 for the tank cover nut
  • A torque wrench to tighten the cover nut to 50 foot-pounds

Label all fuel hoses before disconnecting them so you can reconnect them correctly. The pump assembly is turned counterclockwise to unlock and clockwise to lock .

The Cost of a Faulty Fuel Pump Relay: What You Might Actually Be Dealing With

Diagnosing a fuel pump issue on a 2006 A4 can be tricky because several components can produce the same symptoms. In addition to the relay and the pump itself, you may also need to inspect the fuel pump control module (located near the pump) and the wiring harness between the relay and the pump.

One owner story from 2015 highlights a situation where cold weather made fuel delivery impossible. After replacing the relay, warming the ECU, and even charging the battery overnight, the car still would not start. The fix came from heating the pump module in the trunk area with a hair dryer, confirming that the pump module was frozen . This is a useful reminder: not every "no priming" issue is caused by the relay.

If you have gone through the relay testing and the relay is fine, the next most likely suspects are:

  1. The fuel pump itself – worn out or electrically dead
  2. The fuel pump control module – the small electronics module attached to the pump flange
  3. The fuel filter – a clogged filter can cause the pump to work harder and fail prematurely

KEMSO Fuel Pumps: A Smart Choice for Your 2006 Audi A4

When the time comes to replace the fuel pump itself, you want a part that is reliable, durable, and built to match your Audi's original specifications. KEMSO is a fuel pump brand that delivers exactly that. Every KEMSO Fuel Pump is designed as a direct OEM replacement, which means it matches the original equipment for voltage, amperage, pressure, flow rate, and connector fitment. You get consistent fuel delivery whether you are commuting on the highway or sitting in traffic on a hot summer day .

KEMSO pumps are constructed with high-quality materials that resist corrosion and wear. The motor is sealed to prevent fuel contamination, and every internal component is tested for durability. Unlike some budget pumps that fail after a few months, KEMSO fuel pumps are engineered to last . Every pump comes with a Lifetime Warranty. If a KEMSO pump ever fails due to a manufacturing defect, the company replaces it free of charge .

The wiring connector on a KEMSO pump matches your Audi's original harness, so you do not need to cut or splice any wires. Installation is as close to plug-and-play as it gets. Whether you drive a compact sedan or a high-performance European model, KEMSO has a fuel pump that fits. The product line covers hundreds of vehicle models, and you can check compatibility easily on their site .

Visit https://www.kemsoracing.com/ today to find the correct KEMSO fuel pump for your 2006 Audi A4. Their team can help you confirm fitment and answer any installation questions. For a fuel pump you can trust for the long haul, KEMSO is the choice.

Final Thoughts

Finding the fuel pump relay on a 2006 Audi A4 is usually a simple process, but it can become confusing when you factor in different engine codes and occasional cold-weather quirks. Start by checking the relay behind the driver's side dash panel. If that does not solve your issue, test the relay with a multimeter, inspect the fuel pump fuse, and don't forget to consider the freezing issue that has plagued owners in colder climates .

Always keep the fuel system in mind as a whole. The relay, the pump, the controller module, and the fuel filter all work together. A systematic approach will help you pinpoint the fault quickly and avoid replacing parts that are still good.

When replacement is necessary, choose a quality part. The relay is a small purchase, but the fuel pump is a job you do not want to do twice. With KEMSO's lifetime warranty and OEM-grade construction, you can have peace of mind knowing your 2006 A4 will start reliably for years to come. For all your fuel pump needs, get the best with KEMSO at https://www.kemsoracing.com/.


Back to blog