BMW Integral Active Steering explained: how rear-wheel steering works

BMW Integral Active Steering is a system that steers the rear wheels as well as the front wheels. At low speeds it makes a large car feel smaller and easier to park, and at high speeds it makes the car more stable during lane changes.

It is offered on many larger BMW models and on some M cars. In this article we explain how BMW Integral Active Steering works, its benefits, how it differs from the earlier Active Steering system and what owners should know about maintenance.

From Active Steering to Integral Active Steering

BMW introduced Active Steering in the early 2000s on the 5 Series. This system changed the ratio of the front steering depending on speed: more direct at low speeds for easy manoeuvring, and less direct at high speeds for stability. It used a planetary gear and an electric motor in the steering column.

Integral Active Steering came later and added rear-wheel steering. It combines a variable front steering ratio with an electric actuator on the rear axle that can turn the rear wheels by a few degrees.

How BMW Integral Active Steering works

The system constantly reads information such as vehicle speed, steering angle, yaw rate and lateral acceleration. A control unit calculates the ideal rear-wheel angle and moves the rear wheels using an electric actuator.

The behaviour depends on speed:

• At low speeds, the rear wheels turn in the opposite direction to the front wheels. This reduces the turning circle and makes the car feel shorter and more agile in town and car parks.
• At higher speeds, the rear wheels turn in the same direction as the front wheels. This makes lane changes smoother and more stable, because the car moves sideways with less yaw.

The angles are small, but the effect is clearly noticeable, especially on long and heavy cars.

Benefits in everyday driving

Owners notice the benefits of BMW Integral Active Steering in several situations:

• Parking and manoeuvring: a smaller turning circle makes large saloons and SUVs easier to park.
• Town driving: tight junctions and roundabouts need less steering effort.
• Mountain roads: the car turns in more willingly in tight hairpins.
• Motorways: lane changes feel calm and stable, even at high speeds.
• Towing and loads: extra stability helps when the car is heavily loaded.

For many owners, it makes a large car feel one size smaller.

Integral Active Steering on M cars

Some BMW M models, especially larger and heavier ones, use Integral Active Steering to combine agility with stability. In these cars, the system is tuned for a sportier response, helping the car rotate into corners and stay stable under high-speed braking and direction changes.

The system works together with other chassis systems, such as adaptive suspension, active roll stabilisation and the Active M Differential. Our articles on Adaptive M Suspension and the Active M Differential explain these systems.

Does it feel natural?

Some drivers worry that rear-wheel steering will feel artificial. In practice, BMW tunes the system to feel natural, and most drivers quickly forget it is there.

The first time you drive a car with Integral Active Steering, you may notice that the car turns more sharply than expected at low speeds. After a short time, this feels normal and makes manoeuvring easier. At high speeds, the effect is subtle and mainly felt as extra stability.

Maintenance and common issues

Integral Active Steering is generally reliable, but it adds components to the rear axle:

• The rear actuator can develop leaks in its protective boots or electrical faults. A warning message usually appears if the system has a problem.
• Wheel alignment must be done correctly, with procedures that consider the rear steering. Our article on BMW wheel alignment explains why this matters.
• Steering angle sensors must be calibrated after certain repairs.
• Battery voltage affects many electronic systems, including the steering.

When a fault occurs, the system usually switches to a safe mode with the rear wheels held straight, so the car remains drivable.

Buying a car with Integral Active Steering

When buying a used BMW with this option:

• Check that no warning messages appear on the test drive.
• Test manoeuvring at low speed to feel the reduced turning circle.
• Ask for the alignment history and any repairs to the rear axle.
• Have a diagnostic scan done to check for stored faults in the steering systems.

BMW Integral Active Steering is one of the technologies that make modern BMWs so agile for their size. For drivers of larger models, it is often one of the most appreciated options.

BMW Integral Active Steering at a glance

Item	Details
Function	Steers the rear wheels by a few degrees
Low speed	Rear wheels opposite to the front, smaller turning circle
High speed	Rear wheels same direction, more stability
Front steering	Variable ratio depending on speed
Predecessor	Active Steering, front axle only
Found on	Many larger BMW models and some M cars
Fault behaviour	Usually rear wheels held straight in safe mode

Frequently asked questions

What does BMW Integral Active Steering do?

It steers the rear wheels slightly to reduce the turning circle at low speeds and improve stability at high speeds.

Is BMW Integral Active Steering worth it?

For larger models, many owners find it very useful, especially for parking and stability on motorways.

Does rear-wheel steering need special alignment?

Yes. The alignment procedure must consider the rear steering system, and sensors may need calibration.

What is the difference between Active Steering and Integral Active Steering?

Active Steering changes only the front steering ratio. Integral Active Steering also steers the rear wheels.

Sources

• BMW Group PressClub – chassis and steering technology press material
• BMW owner's manuals – Integral Active Steering