Where is the CAS module located in a BMW?
3 Answers
BMW's CAS module is located in the lower left part of the cabin. After removing a plastic panel, look upwards to find a black rectangular computer board containing several modules. The one labeled 'CAS' in English is the module. BMW's main models include: 1 Series, 3 Series, 3 Series GT, 4 Series, and 5 Series. Taking the BMW 3 Series as an example: it is equipped with a low-power version of a 2.0-liter turbocharged four-cylinder engine, codenamed B48B20B, with a maximum power of 135 kilowatts and a maximum torque of 300 Newton-meters. The maximum power speed ranges from 5,000 to 6,000 revolutions per minute, and the maximum torque speed ranges from 1,350 to 4,000 revolutions per minute. In terms of appearance, the BMW 3 Series features more fluid and powerful body lines, especially the two raised V-shaped lines on the engine hood, which make the front of the car look more powerful.
When working on BMW repairs, I found that the CAS module is usually quite well hidden, primarily located in the driver's footwell area. By removing the trim panel under the steering wheel or lifting the carpet for a closer look, you can spot it near the steering column or pedal area—specific placement varies significantly by model. Older models like the E90 typically have it fixed in the front left corner, while newer ones like the F30 may relocate it behind the glovebox or under the center console. If it's hard to locate, don't force it—the CAS manages key recognition and the anti-theft system, and misalignment could leave the car completely immobilized. For such issues, it's best to use a diagnostic tool to check fault codes rather than randomly disconnecting wires and risking a short circuit. Daily driving should avoid exposing the module to moisture, as water ingress can cause malfunctions. Replacing the CAS also requires reprogramming and key matching, which is a technical task. When checking its location, consult the vehicle manual or online tutorials—experience makes the job much easier.
After years of tinkering with BMW modifications, I know the CAS module location like the back of my hand. It's usually hidden around the driver's footwell area, most commonly near the steering column or foot pedal corner. On E-chassis models, you'll often find it right below the knee, while F-chassis may relocate it to the side of the center console. Why does location matter? The CAS handles key signals to control ignition - if it's moved or fails, your car won't start. When I installed a smart key once, I worked on the CAS interface positioned snugly against the steering wheel wiring harness; always disconnect the battery to prevent shorts. Can't locate it? Snap an interior photo and ask on car forums for precise guidance. Preventive tip: regularly clean footwell dust to avoid blocking cooling vents, as CAS failure often causes remote malfunction - check fuses first before dismantling. Pro tip from enthusiasts: consult model/year diagrams for accurate positioning details.
