Upgrade Your Mercedes C250 with Aftermarket CarPlay

For Mercedes-Benz C250 owners looking to modernize their in-car experience, installing an aftermarket CarPlay system is a fantastic upgrade. This guide will walk you through the process, drawing on real-world experience to help you seamlessly integrate Apple CarPlay into your C250. We’ll cover everything from choosing the right kit to step-by-step installation, ensuring you can enjoy smartphone integration in your Mercedes.

Choosing the Right Aftermarket CarPlay Kit for Your C250

Several aftermarket CarPlay options are available for the Mercedes-Benz C250, each with its own set of features and price points. Two popular andDIY-friendly choices stand out: Road Trip and Joyauto. While Unique Auto Developments also offers a kit, it tends to be significantly more expensive.

When comparing Road Trip and Joyauto, both offer similar functionality, bringing CarPlay to your factory screen. However, a key difference lies in microphone integration. The Road Trip kit utilizes your Mercedes C250’s built-in microphone for both standard phone calls and Siri voice commands. Joyauto, on the other hand, uses the car’s microphone for calls but requires a separate microphone for Siri and Google Assistant. Given this, and considering the readily available purchase option on Amazon, the Road Trip kit often presents a more convenient and integrated solution for C250 owners. The price difference between these two is also minimal, making Road Trip a compelling choice for many.

Step-by-Step Guide to Installing Aftermarket CarPlay in Your Mercedes C250

Preparation is Key:

Before starting the installation, gather the necessary tools. A trim removal kit is essential to protect your Mercedes’ interior from damage. A quality kit, like a 41-piece set available on Amazon, provides a variety of tools that are invaluable for safely removing trim panels and accessing the car’s electronics. These tools distribute pressure effectively, minimizing the risk of cracking or breaking plastic components.

Accessing the Radio Unit and Connections:

1. Remove the Upper Trim: Begin by carefully removing the trim piece located above the radio, which includes the air vents and the decorative “swish” extending towards the door. Using a trim removal tool, gently pry behind the trim, starting near the door. The clips will release relatively easily until you reach the vents, where more pressure may be needed to dislodge the firmly secured vent section.
2. Disconnect the Vent Assembly: Once the upper trim is loose, disconnect the wiring harness for the air vent controls and carefully set the entire vent assembly aside.
3. Glove Box Access for Module Placement: Creating space for the CarPlay module is crucial. The ideal location is often found between the glove box and the radio cavity. To access this area, start in the passenger compartment and locate three screws underneath the dash that secure the rear trim piece. Remove these screws. Gently pull the trim down and reach behind it to release a large “L” shaped hook, which may require a slight leftward movement for release. Wiggle the trim piece out and disconnect the passenger light wire.
4. Side Trim Panel Removal: Next, remove the trim panel on the far right side of the dashboard, situated between the glove box and the passenger door. This piece is held in place by four pop-out clips and should wiggle free with gentle persuasion.
5. Glove Box Screw Access: With the side trim removed, you can now access the first of the glove box screws, located at the bottom where the trim panel was removed. Locate and remove the matching screw on the opposite side of the glove box.
6. Interior Glove Box Screws: Open the glove box and locate four screws at the top interior. Remove these screws as well.
7. Detach the Glove Box: Your glove box should now be loose and able to be pulled down and away from the dashboard. It may require a slight wiggle. Carefully disconnect all wiring harnesses attached to the glove box and set it aside.
8. Radio Security Screw Access: With the glove box removed, you can now access the two locking screws securing the radio unit. These silver screws are located at the top of the radio cavity, where the vent assembly was previously positioned.
9. Release the Radio Locking Mechanism: Unscrew the two silver screws completely. These screws engage a mechanism that locks the radio onto rails. Once unscrewed, insert a screwdriver into the screw holes and gently but firmly tap the screwdriver with your palm. This action will disengage the security rails, allowing the radio to slide forward.
10. Slide Out the Radio Unit: Carefully slide the radio unit out of the dashboard.
11. Locate and Disconnect the Main Wiring Harness: Identify the main wiring harness block at the back of the radio. It’s a large, square plastic connector, typically located on the bottom, closer to the driver’s side. Locate the lever on the edge of this block and pull it back to release the harness.
12. Fiber Optic Cable Transfer (if applicable): Inspect the removed harness for fiber optic wires entering the upper right side of the connector. These are often orange. If present, use a pin tool from your trim removal kit to depress the lock on each fiber optic cable and gently pull them out. It is crucial to transfer these fiber optic cables to the same positions on the new pigtail harness included with the Road Trip kit.
13. LVDS Cable Identification and Connection: The instructions may refer to a blue LVDS cable, but in some Mercedes C250 models (like the W204), this cable might be GRAY. Identify your LVDS cable (likely gray or dark blue) and disconnect it from the back of the radio. Connect the disconnected LVDS plug into the BLUE splitter cable provided with the Road Trip kit. Then, connect one end of the splitter back into the radio (blue plug to the gray/blue input) and the other end to the Road Trip module.
14. Connect the Pigtail Wiring Harness: Connect the Road Trip pigtail wiring harness to the radio unit. Push the lever down on the connector to secure it in place.

Configuring the Road Trip Module and Audio Connection:

1. Set Module Jumpers: On the Road Trip module, set the jumpers according to the instructions provided for your specific Mercedes C250 model year. For a 2014 C300 W204, the configuration might be jumpers 3, 5, and 8 set to ON, with the rest OFF. Consult your module’s manual for the correct settings.
2. Route Wires and Position the Module: Route the wires from the radio compartment through the designated hole leading to the glove box cavity. This hole is often shared by the vent wiring. Position the Road Trip module in the space between the radio compartment and the glove box. With connectors facing upwards and the wireless antenna wire at the bottom, it should fit snugly.

Connecting Audio via AUX Input (if necessary):

If your Mercedes C250 has an AUX input in the glove box, connecting the audio cable is straightforward. However, if, like in the original article, your AUX input is located in the center console, the following steps detail a method for running the audio cable discreetly:

1. Shifter Boot Removal: Use a pry tool to lift the shifter boot. It is held by four snaps and should come off easily.
2. Gear Knob Removal: Turn the shifter boot inside out over the gear knob to expose the retainer nut. Twist the nut counter-clockwise and slide it down the shaft. You can then pull the gear knob and boot off. You might need to put the car in neutral to remove the knob, remember to put it back in park afterwards.
3. Aluminum Trim Removal: Pry up the aluminum trim surrounding the shifter boot. It is held on firmly, so apply firm but controlled pressure while prying. It will pop off.
4. Access Center Console Storage: Remove the rubber liner in the small storage compartment in front of the center console to reveal a Torx screw. Remove this screw.
5. Remove Center Console Trim: Pry up the trim piece that was secured by the Torx screw. It has four clips and will detach when gently pried at a corner.
6. Locate Console Torx Screws: Once the trim is off, you’ll find three more Torx screws. One secures the COMAND assembly, and the others hold the remaining console trim.
7. Route the Audio Cable: With the trim removed, you should be able to see under the center console. Use trim tools to carefully push the 3.5mm audio cable upwards towards the carpet seam near the shifter. This seam is an ideal spot to feed the connector up and grab it from above. Feed enough wire so you can retrieve it near the shifter.
8. Center Console Storage Access: Open the center console storage compartment. If equipped with USB and AUX plugs, there will be a black plastic liner clipped inside. Pry off this liner from the side of the storage compartment. This will allow you to move the insert around slightly.
9. Fish the Audio Cable: Use a coat hanger, bent into a hook with a looped end to avoid snagging, to fish the 3.5mm audio connector from the opening in the center console (near the cupholders) to the now loosened storage compartment.
10. Connect and Conceal the Adapter: Attach the 3.5mm connector to the coat hanger and carefully pull it back through, guiding the connector into the storage compartment. Connect the 3.5mm plug to the provided adapter and plug it into the AUX port. Tuck the adapter and excess wire behind the plastic insert in the storage compartment for a clean look.
11. Reassemble Center Console: Snap the plastic insert back into place in the storage compartment, tucking any remaining slack wire under the center console. Reassemble the center console trim pieces.

Final Checks and Reassembly:

1. Test the System: Before fully reassembling, test the CarPlay system. Turn on the car, connect your phone via USB (for initial testing of both wired and wireless CarPlay/Android Auto). Press and hold the “CLEAR” button on your COMAND system. CarPlay should appear on the screen. Verify audio and navigation using the COMAND dial. Troubleshoot any issues: no screen display might indicate an LVDS cable connection issue, no sound points to the 3.5mm audio cable, and no power suggests a problem with the main wiring harness connection.
2. Reverse Installation Process: Once everything is working correctly, begin reversing the installation steps to reassemble your dashboard and center console.
3. Radio Unit Reinstallation: Slide the radio back into place, stopping about 2 inches from fully seated. Tuck the large pigtail connector block into a void beneath the radio unit. While sliding the radio in, pull any slack from the Road Trip wires to prevent snagging.
4. Engage Radio Locking Mechanism: Use a hook tool to pull up the radio locking levers on each side. Hold them in the uppermost position while starting a few threads of the screws. Tighten the screws just enough to secure them but still allow the locking mechanism to move. Push down on the screws to drop the locking mechanisms slightly, allowing the radio to slide in completely.
5. Secure Radio and Mount Antenna: Slide the radio fully into place until it snaps in. Tighten the two screws at the top to fully engage the locking mechanism and secure the radio. Use electrical tape to secure the wireless antenna to the plastic trim between the two screws at the top of the radio cavity.
6. Reconnect Vent Assembly: Plug the vent wire back in and reinstall the vent and vent trim piece.
7. Position CarPlay Module and Reinstall Glove Box: Wiggle the Road Trip module into the space between the glove box cavity and the radio. Ensure connectors are facing up and the antenna wire is at the bottom for a clean fit. Route the USB port for accessibility. Reinstall the glove box, bottom cover, and side cover.
8. Cabin Air Filter (Optional): With the glove box removed, consider replacing your cabin air filter, which is now easily accessible.

This detailed guide, while appearing lengthy, breaks down the installation into manageable steps. With careful execution and the right tools, upgrading your Mercedes C250 with aftermarket CarPlay is a rewarding DIY project that significantly enhances your driving experience.