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.
Using An After Market Radio Unit
The accessory electronic module (AEM) (4/78) makes it possible to automatically control the telemute function, display lighting and speed-adapted volume control when using an aftermarket radio unit. This is on the condition that the aftermarket radio unit supports these functions. The accessory electronic module (AEM) receives a speed signal (volume adaptation) via the CAN-net and brightness of the display lighting via rheostat from the central electronic module (CEM) (4/56).
The accessory electronic module (AEM) also receives a mute signal from the reverse warning system and external hands-free unit and transmits it on to the radio unit.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.
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