More about the product
Steering Wheel Control Harness
The Aerpro CHMC4C Steering Wheel Control Interface (SWC) allows you to upgrade to an aftermarket headunit whilst maintaining use of your factory steering wheel controls. Engineered to suit various Mercedes vehicles with Audio 20 original stereo and with QUADLOCK connector, the steering wheel control interface includes a harness that is fitted with a vehicle specific plug designed to connect directly into the existing wiring in the vehicle with ease, no cutting of the factory wiring harness in the vehicle is required.
Installation of the aftermarket headunit is simplified even further when paired with the optional Aerpro APP9 Headunit Secondary ISO Harness & SWC Patch Lead, which connects between the aftermarket headunit and the Aerpro Steering Wheel Control Interface. This interface is CANBUS compatible and provides various outputs including Reverse Trigger, Park Brake, Speed Pulse and Illumination.
Please Note:
- Steering Wheel Control Interfaces vary between models, to find the correct part for your vehicle use the Aerpro Vehicle Selector.
- A Steering Wheel Control Patch Lead is required to be used in conjunction with this part to enable Steering Wheel Controls to function (sold separately).
- Aftermarket headunit must be SWC compatible and Steering Wheel Control Functions may vary from the OEM Functions.
- Suitable for vehicles with Audio 20 original stereo and with QUADLOCK connector.
- Due to the audio options fitted from factory we recommend removing the factory unit to confirm the compatibility if the harness prior to purchase.
- Not compatible with OEM amplified systems.
Important Notes:
- Allows you to upgrade to an aftermarket headunit whilst maintaining use of your factory steering wheel controls
- Increases driver safety by allowing you to keep your hands on the steering wheel and eyes on the road
- Supports OEM Phone Button when connected to compatible aftermarket bluetooth headunits
- Suitable for non OEM Amplified vehicles with Audio 20 original stereo and with QUADLOCK connector
- CAN-BUS integration compatible, no additional modules required for CAN-BUS vehicles
- Provides output feeds for reverse trigger, park brake, speed pulse and illumination
- Fitted with a vehicle specific plug, no cutting of wires required
- Recommended to be installed with an Aerpro APP9 Headunit Secondary ISO Harness & SWC Patch Lead (sold separately)
- Requires SWC patch lead to provide compatibility with the aftermarket headunit (sold separately)
Inclusions & Notes:
- Interface Type: CANBUS
- Patch Lead Type: C
- Phoen Button Compatibility: Yes (When Enabled From Factory)
- Voice Assistant Support Available: Yes
- For Voice Assistant support the interface requires firmware version xx.3. To update the firmware please contact your Authorised Aerpro Dealer
- If your steering wheel control does not have a Voice Assistant button, the answer button will function as voice support instead
- Aftermarket headunit and phone must also support Voice Assistant feature for this feature to work
- Outputs:
- Reverse Trigger: Yes (Purple)
- Park Brake: Yes (Green)
- Speed Pulse: Yes (Pink)
- Illumination: Yes (Orange)
- AMP Remote: No
- Telephone Mute: No
- Other Retention:
- OEM Amplified System: No
Suitable Vehicles:
- Mercedes CLS 2005-2011 W219
- Mercedes E-Class 2002-2009 W211
- Mercedes SLK R171 2004-2011
Technical details
- Brand
- Aerpro
Look out for Bankstown Sound Recommendations
Why Choose Bankstown Sound for Your Car Audio & Tech Upgrades
At our Bankstown Sound store and workshop in Sydney, our team ensures every car and auto audio installation and upgrade starts with an understanding of how you use your car. Our team works with you to understand your driving habits, the features you rely on, and the problems you’re trying to solve.
Most factory setups are built to broad standards and often lack the clarity or seamless connectivity required for how people actually drive. That’s why we focus on modernising your dashboard and audio performance based on how you use your vehicle.

