Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Alarm, Electrical Control Modules, Brakes, Brake Control Module (BCM) - Design And Function: Alarm: Function: Deactivation
The alarm is deactivated if the vehicle is unlocked using the remote key or using the keyless system. When the central electronic module (CEM) receives an unlock command, it deactivates the alarm and releases the central locking. On vehicles with the keyless entry system, the unlock command is transmitted from the keyless vehicle module (KVM) to the central electronic module (CEM).
Full protection can also be recovered if the function for re-locking is activated. In which case the vehicle will be automatically locked and the alarm activated after approx. 90 seconds provided that none of the doors or the tailgate has been opened.
The alarm functions can also be deactivated locally if the button for unlocking the tailgate/trunk lid is pressed on the remote key. In that case the central electronic module (CEM) takes no account of signals from the contact breaker in the tailgate/trunk lid lock unit. The vehicle tilt sensor and motion sensor will also be deactivated temporarily. To regain full protection for the vehicle the locking button on the remote key must be pressed.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
No obligation. See pricing before you book.