BMW Single Flap Valve Controller – RX1 Remote Exhaust Control Module (BE1) by ASR

Complete Control Over Your BMW’s Single-Valve Exhaust System

Many BMW models come equipped with a single-flap (single valve) exhaust setup. While this design offers subtle control, it’s often tied to the vehicle’s ECU — limiting when and how the flap operates. The BMW Single Flap Valve Controller RX1 (BE1) by ASR offers a plug-and-play solution that hands that control back to you.

Because sound matters as much as performance, this controller lets you open or close your flap on demand with a compact, wireless remote.

Designed for Single-Valve BMW Exhaust Systems

The RX1/BE1 controller is tailored to BMWs that use a single exhaust flap, typically found in non-M or lower-output models, including select 1, 2, 3, 4, and 5 Series vehicles.

Compatible With:

• BMW F30/F31 320i, 328i, 330i, 340i

• BMW F32/F36 420i, 428i, 430i, 440i

• BMW F22 228i, M235i, M240i

• BMW G20 330i with factory valved muffler

• Vehicles with 1x electronic exhaust valve

For dual-valve M or M Performance systems, check out our BMW Dual Valve Controllers.

Remote-Controlled Valve Switching – Anytime, Anywhere

Thanks to the included RF key fob, you can easily toggle your BMW’s exhaust flap between three modes:

• Open Mode: Valve stays open for a more aggressive tone

• Close Mode: Valve remains closed for quiet cruising or stealth starts

• Auto Mode: System reverts to factory ECU behavior

Whether you’re heading out for a spirited drive or sneaking out of your neighborhood, you’ll appreciate the instant flexibility.

No Apps, Coding, or Flashing Needed

Unlike many universal kits or software-based tools, the RX1 module is completely hardware-driven. That means:

• No smartphone pairing

• No coding or diagnostics

• No battery drain from software conflicts

Installation is seamless and doesn’t require a trip to the dealer or a tuning tool.

Plug-and-Play Simplicity

This module uses OEM-style T-harnesses, which means installation is 100% plug-and-play. There’s no wire splicing, cutting, or permanent modification required.

Installation Process:

1. Lift the car and locate the factory exhaust valve

2. Disconnect the OEM connector

3. Insert RX1 module between plug and valve

4. Secure the unit using zip ties or adhesive pad

5. Test the three modes using the remote fob

Because of this clean integration, the module is easy to remove if needed, making it perfect for lease or resale scenarios.

100% CEL-Free – Safe for All BMW Electronics

Thanks to its built-in resistance logic and CAN-bus safety, the RX1 module ensures zero fault codes or dashboard warnings. It’s been bench-tested and road-tested to work across a variety of BMW ECUs without triggering any alerts.

Safe For:

• Drive mode selectors (Comfort, Sport, Sport+)

• OBD2 diagnostics and BMW service tools

• Vehicles with factory ECU flash or light tuning

• Daily drivers and performance builds alike

For tuning-safe builds, the RX1 provides the control you want without interfering with the control systems you rely on.

Compatible With Aftermarket Mufflers That Retain OEM Valve Motors

Many aftermarket mufflers maintain BMW’s factory valve design. The RX1 module works flawlessly with popular systems, including:

• Remus Axle-Back for BMW 330i

• BMW M Performance Exhaust (Single Valve)

• Milltek Sport Valved Mufflers for G20 330i

Even with upgraded hardware, your flap control stays intact — and now, under your complete command.

Compact RF Remote with Instant Operation

The remote is slim, lightweight, and fast — offering mode switching with a simple button press. Since it uses radio frequency instead of Bluetooth, it’s not affected by signal dropouts or connection delays.

You can mount the fob in your cabin, store it in the glovebox, or keep it on your keyring. Because of its efficient design, it won’t interfere with your keyless system or drain the car’s power.

Built for Long-Term Reliability

Because undercar environments can be brutal, ASR has built this controller to withstand heat, moisture, and vibration. The controller box is sealed and includes reinforced wiring for durability in all weather and driving conditions.

Whether you’re daily driving, road-tripping, or enjoying spirited weekend runs, this unit will hold up reliably.

Why Choose RX1/BE1 by ASR?

Many “cheap” universal modules risk error codes or incomplete compatibility. The RX1 from ASR is built for BMWs, tested across platforms, and trusted by thousands of enthusiasts.

Key Benefits:

• No coding, no apps

• Three dynamic modes

• 100% plug-and-play

• Error-free, CEL-safe

• Compact and easy to use

• Compatible with factory or valved aftermarket systems

Pair it with our Carbon Fibre Rear Diffuser for F30 or BMW Sport Intake Kits for a well-rounded upgrade path.

The device offers the following modes:

This device has been specially developed for use on electric flap systems and thus provides safe and permanent operation.

Rely on our quality!

Brand product Made in Germany!