Where to Find the Fuel Pressure Regulator on a 2013 Audi A4

The fuel pressure regulator on a 2013 Audi A4 is not a single, easily removable part like on older vehicles; instead, pressure regulation is integrated into the high‑pressure fuel pump on the engine and into the fuel delivery module in the tank. In practice, technicians usually refer to these assemblies—rather than a standalone “regulator”—when diagnosing fuel pressure issues on this model.

Understanding the Fuel System on the 2013 Audi A4

The 2013 Audi A4 (particularly the commonly sold 2.0 TFSI engine) uses a modern, dual‑stage fuel system: a low‑pressure system in the tank and a high‑pressure system on the engine. Because of this design, what used to be a separate, easily identifiable fuel pressure regulator is now built into other components, and actual fuel pressure control is largely handled electronically through the engine control unit (ECU) and sensors.

Main Locations Involved in Fuel Pressure Regulation

1. High‑Pressure Side: On the Engine (High‑Pressure Fuel Pump)

On the 2013 Audi A4, the closest equivalent to a traditional fuel pressure regulator on the engine is integrated into the high‑pressure fuel pump. This pump supplies the fuel rail for the direct‑injection system and is responsible for generating—and regulating—the very high pressures needed at the injectors.

The following list describes where to find this component and how it functions in relation to fuel pressure regulation.

• Location on the engine: The high‑pressure fuel pump is mounted on the cylinder head, typically at the rear or side of the engine (on the 2.0 TFSI, it is usually on the right‑hand side of the engine when looking from the front of the car). It is driven mechanically by a camshaft lobe.
• Metal fuel line connection: You will see a rigid metal fuel line running from the pump to the fuel rail on top of the engine. This is a key visual clue you’ve located the high‑pressure pump.
• Integrated pressure control valve: Inside this pump is an electronically controlled metering or pressure control valve, which performs the role that a separate fuel pressure regulator would have done on older systems.
• Fuel rail pressure sensor nearby: The fuel rail includes a pressure sensor that reports real‑time pressure to the ECU, which then adjusts the pump’s internal valve accordingly.
• No separate “bolt‑on” regulator on the rail: Unlike earlier port‑injection systems, there is typically no stand‑alone regulator canister attached directly to the fuel rail with a vacuum line.

In everyday workshop practice, when technicians speak of the “fuel pressure regulator” on a 2013 A4’s engine, they are usually talking about the pressure control valve within the high‑pressure pump and the way the ECU commands it.

2. Low‑Pressure Side: In the Fuel Tank (Fuel Pump / Fuel Delivery Module)

Fuel pressure is also controlled at the low‑pressure side, inside the tank. Here, the main component is the fuel pump module, which includes the in‑tank pump and, on many variants, an integrated pressure‑limiting or regulating function. This keeps the supply pressure feeding the high‑pressure pump within a defined range.

The following points explain how the in‑tank components relate to fuel pressure regulation and where they are located.

• Under the rear seat or trunk floor: Access to the in‑tank fuel pump module is usually via a round access panel under the rear seat base or under the trunk floor, depending on exact body style and market.
• Fuel pump module assembly: The component you see when the access cover is removed is the large plastic fuel pump (or “fuel delivery”) module. This unit often incorporates a pressure regulating/limiting function for the low‑pressure circuit.
• Low‑pressure supply to engine: A fuel line runs from this module, along the underside of the car, to the engine bay. The pressure at this stage is much lower than the high‑pressure side, but it still must be controlled within specification.
• Electronic control via module/ECU: On many A4s, the fuel pump is controlled by a dedicated fuel pump control module or directly by the ECU, which adjusts pump speed or duty cycle according to demand.
• No separate inline regulator under the car: Most 2013 Audi A4 configurations do not use a separate, frame‑mounted fuel pressure regulator in the fuel line; the function is inside the module and controlled electronically.

From a service perspective, any low‑pressure “regulation” issue on this model is typically addressed by diagnostics on the in‑tank pump module or its control electronics, rather than replacing a separate regulator on the chassis.

How the System Works Together

The 2013 Audi A4’s fuel system uses sensors and control valves instead of one simple mechanical regulator. The ECU monitors fuel pressure on the rail, as well as low‑pressure feed from the tank, and continuously adjusts pump outputs to keep pressure within strict limits for emissions, performance, and efficiency.

The list below outlines how the different parts interact to control fuel pressure in real time.

1. In‑tank pump delivers low‑pressure fuel: The pump module in the fuel tank sends fuel forward at a controlled, relatively low pressure to the engine bay.
2. High‑pressure pump raises pressure: At the cylinder head, the cam‑driven high‑pressure pump compresses the fuel to the high pressure required for direct injection.
3. Fuel rail pressure sensor reports values: A sensor on the rail constantly feeds actual pressure data back to the ECU.
4. ECU commands the pump control valve: Based on sensor data and engine load, the ECU adjusts the metering valve in the high‑pressure pump to increase or decrease pressure.
5. Safety and return functions: Any over‑pressure or abnormal situation is handled by built‑in safety logic and, where fitted, pressure‑limiting functions inside the pump or module.

This integrated, sensor‑driven approach means fuel pressure regulation is effectively spread across sensors, the ECU, and the pump assemblies, rather than resting in a single, easy‑to‑spot “regulator” canister.

What This Means If You’re Troubleshooting

If you’re trying to locate the “fuel pressure regulator” on a 2013 Audi A4 because of drivability problems—hard starts, loss of power, misfires, or fuel rail pressure fault codes—the answer is that you’ll be working with the high‑pressure pump assembly, the in‑tank pump module, and the relevant sensors and control modules.

The following list summarizes practical checks and components most often involved when owners suspect fuel pressure problems on this model.

• Check for stored fault codes: Use a scan tool (ideally VCDS or ODIS) to look for fuel rail pressure or low‑pressure fuel system codes, which can point toward the high‑pressure pump, rail sensor, or in‑tank pump.
• Inspect the high‑pressure pump area: Look for fuel leaks or damage around the cam‑driven pump and its metal lines; any external leak must be addressed immediately.
• Test fuel rail pressure readings: Compare live data from the fuel rail pressure sensor with factory specifications to see if the pump is meeting commanded pressure.
• Check low‑pressure supply: With appropriate equipment, verify that pressure from the in‑tank pump is within spec; low feed pressure will prevent the high‑pressure pump from performing correctly.
• Consider professional diagnosis for internal faults: Because the pressure control valve is integrated into the high‑pressure pump and governed by the ECU, accurate diagnosis often requires professional tools and documentation.

Instead of hunting for a small, vacuum‑line‑equipped regulator, owners should approach the 2013 A4’s fuel system as a set of coordinated, electronically controlled assemblies, with the high‑pressure pump and in‑tank pump being the main hardware involved.

Summary

On a 2013 Audi A4, fuel pressure regulation is built into the fuel system rather than handled by a separate, easily identifiable regulator. On the engine, the regulating function resides in the high‑pressure fuel pump mounted on the cylinder head, working together with the fuel rail pressure sensor and ECU. In the tank, the fuel pump module provides controlled low‑pressure supply and may include a regulating or limiting function. As a result, anyone troubleshooting fuel pressure issues on this model will focus on these pump assemblies, sensors, and control electronics rather than searching for a standalone fuel pressure regulator component.

Where is my fuel pressure regulator located?

Your fuel pressure regulator is likely located on the fuel rail at the front of the engine or inside the fuel tank. If it’s on the fuel rail, you will find it at one end, often near where a vacuum hose connects to it. If your vehicle has a “returnless” fuel system, the regulator is integrated with the fuel pump assembly inside the fuel tank. To be certain, consult your vehicle’s owner’s manual. 
This video shows the location of the fuel pressure regulator on a specific vehicle: 57sPhillips VisionYouTube · Nov 23, 2021
Location details:

• On the fuel rail:
  • This is common for many vehicles, especially those with a return-style fuel system. 
  • It will be attached to the fuel rail, which is the long fuel line that supplies injectors on top of the engine. 
  • It is often easy to spot because of the vacuum hose attached to it. 
• In the fuel tank:
  • This is common for “returnless” systems where there is no return fuel line to the tank. 
  • The regulator is part of the fuel pump module, which is located inside the fuel tank. 
  • This location is less accessible, as it requires accessing the fuel tank itself. 

You can watch this video to see how to replace the fuel pressure regulator: 58sPhillips VisionYouTube · Nov 27, 2021
How to confirm its location:

• Check your owner’s manual: The most reliable way to find the exact location for your specific car model is to check the owner’s manual or a repair manual. 
• Look for a vacuum hose: If the regulator is on the fuel rail, it will be at one end and will have a vacuum hose connected to it. 
• Perform an online search: Search online for “[Your Car’s Make and Model] fuel pressure regulator location” to find specific diagrams and instructions. 

How do I tell if my fuel pressure regulator is bad?

Symptoms of a bad fuel pressure regulator include poor engine performance like misfires, rough idle, and reduced acceleration, along with potential issues like reduced fuel efficiency, black smoke from the exhaust, and a check engine light. You may also notice a fuel smell, or find gasoline in a vacuum hose, which indicates a leak from a failed diaphragm. 
Performance and engine-related symptoms

• Poor acceleration: The engine may hesitate or sputter when you press the gas pedal. 
• Reduced fuel efficiency: The engine may burn more fuel than it should, leading to more frequent stops at the gas station. 
• Engine misfires: You might feel the engine stutter or run roughly, potentially triggering a “random misfire” code (P0300). 
• Rough or high idle: The engine may run unevenly while idling. 
• No-start or hard-start conditions: The engine may crank for a long time before starting, or fail to start at all. 
• Stalling: The engine may cut out suddenly, especially when accelerating or decelerating. 
• Black smoke: The exhaust may produce black smoke, indicating the engine is running “rich” and burning too much fuel. 
• Fluctuating RPMs: The engine’s revolutions per minute may surge or drop unexpectedly while driving. 

Other symptoms

• Check Engine Light: A malfunctioning fuel pressure regulator can trigger the check engine light. 
• Gasoline smell: A strong smell of gasoline can indicate a leak. 
• Fuel in vacuum hose: If the regulator’s diaphragm fails, fuel can leak into the vacuum hose connected to it. 
• Fuel leaks: You may see physical fuel leaks around the fuel rail or injectors. 
• Blackened spark plugs: A rich fuel mixture can cause spark plugs to become fouled with soot. 

What are the symptoms of a bad high pressure fuel pump on an Audi A4?

When you press the gas the engine demands more fuel. Instantly. If the pump can’t keep up you’ll feel a sluggish response hesitation or jerking. Especially during quick acceleration.

Where is the fuel pressure regulator on the Audi A4?

The Audi A4 fuel pressure regulator is typically located on the fuel rail at the end of the fuel line before it returns to the tank. On some models, especially turbocharged ones, the fuel pressure regulator may be integrated into the high-pressure fuel pump (HPFP), which is often located at the top or back of the engine. 
Location by model type

• Naturally aspirated engines (e.g., 3.2L V6):
  • Find the fuel rail, which is a metal pipe that supplies fuel to the injectors. 
  • The regulator will be attached to the end of this rail, where a vacuum hose and the return fuel line connect. 
• Turbocharged engines (e.g., 2.0T):
  • Check the high-pressure fuel pump (HPFP). 
  • The regulator is likely integrated within the HPFP assembly itself. 
  • The HPFP is usually located at the back of the engine, often on top of the valve cover. 

This video shows the location of the fuel pressure regulator on an Audi A4 3.0 V6: 59sAUTOMOTIVE SOLUTIONSYouTube · Feb 21, 2018