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.
Car Access System 4
As soon as the Car Access System 4 receives the signal from the remote control receiver, it checks whether the ID transmitter is valid and belongs to the vehicle. Only if the check is successful will the Car Access System 4 forward the request to the central locking.
The check, also referred to as authentication, takes a few milliseconds. As the master control unit of the central locking system, the Car Access System 4 grants authorization for control of the central locking system.
The junction box electronics module receives the enable via the K-CAN2.
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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.