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.
Central Electronic Module (CEM): Function: Horn
The horn (16/10-11) is located behind the radiator grille. The horn is supplied power from the horn relay (2/17) in the engine compartment fuse and relay box. The horn is activated when a switch in the steering wheel is closed. The closure is detected by the steering wheel module (SWM) (3/130), which sends a signal to the central electronic module (CEM) (4/56). The central electronic module (CEM) forwards a ground closure on one of its outputs, grounding the signal horn relay and activating the relay.
The horn is grounded in the body.
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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.