Steering Wheel Controller | Mercedes S-Class | 708

Download Basic Installation PDF

This printable PDF contains basic Connection and Programming instructions. Return to this page for more detailed instructions, troubleshooting, and additional information.

Steering Wheel Controller-Mercedes S-Class-708.pdf1.8 MB

Vehicle Installation Instructions

The instructions below will guide you through the installation of the Steering Wheel Controller in your vehicle.

NOTE Though Metra has done extensive research, testing, and verification that the Steering Wheel Control (SWC) wires for the listed vehicles are accurate, it is the installer’s responsibility to verify that the Steering Wheel Control wires are installed correctly. If a discrepancy is found after following all instructions, please notify Technical Support.

Connections

Aftermarket Radio Harness

1. Connect Pin 6 of the Steering Wheel Controller harness to the Black ground wire of the aftermarket radio.
2. Connect Pin 12 of the Steering Wheel Controller to the Red accessory wire of the aftermarket radio (shown below).

Vehicle Connection(s) to Factory Harness  

1. Connect Pin 1 of the Steering Wheel Controller (Pink wire) to the wire in Pin 2 of the vehicle's radio harness (shown below).
2. Connect Pin 7 of the Steering Wheel Controller (Blue/Pink wire) to the wire in Pin 4 of the vehicle’s radio harness (shown below).

TIP The connection to this wire will commonly need to be made on the factory harness side of the connector.

→→ Splicing the Steering Wheel Control Wire to the Connector

TIP At minimum, the connection point must be protected with a non-conductive tape (such as electrical tape).

Follow the steps below to splice the SWC wire into the connector wire:

1. Locate the wires entering the connector at Pin 2 and Pin 4.

2. Carefully strip away a half-inch section of each wire covering using a wire stripping tool.

3. Twist both the Pink (Pin 2) SWC wire and the Blue/Pink (Pin 4) SWC wire around the exposed wire sections created in Step 2.

NOTE Ensure the SWC wire is secured to the connector wire.

4. Secure the splice between the connector wire(s) and the SWC wire(s) with non-conductive electrical tape.

WARNING Wire color depicted does not necessarily represent the actual wire color in the vehicle.

SWC 3.5 Jack Connections

For radios with a 3.5mm port located on the rear, plug the male 3.5mm jack directly into the back of the radio.

1. Connect the 3.5mm Jack to the SWC (Steering Wheel Control) input on the back of the radio. This can be achieved through one of the methods detailed in the following sections.

Kenwood/JVC Radios with Single SWC wire

1. Connect the Blue/Yellow wire labeled  Steering Wheel Remote Input to the Brown wire of the female 3.5mm jack.
2. Plug in the male 3.5mm jack into the female 3.5mm jack.

NOTE Kenwood & JVC radios may list their SWC wire as a Marine Remote. Refer to your radio manual if you are unsure. Radios will typically auto-detect as a Kenwood, or need to be force-programmed to a Kenwood radio type (refer to Changing Radio Type below). Contact Technical Support for situations in which the above note isn’t the case.

→ Kenwood & JVC Radio Troubleshooting

If your Kenwood or JVC radio has the connector displayed below (Figure A) and you experience issues programming the SWC, please review this troubleshooting guide before contacting Technical Support.

Universal 2-Wire Radios

1. Connect the steering wheel control wire, Key-A or SWC-1, to the Brown wire of the connector.
2. Connect the remaining steering wheel control wire, Key-B or SWC-2, to the Brown/White wire of the connector.
3. The SWC (Steering Wheel Controls) functions will need to be programmed within the radio. Refer to Radios with Built-In SWC Menus below.

Universal 3-Wire Radios

1. Connect the steering wheel control wire, Key-A or SWC-1, to the Brown wire of the connector.
2. Connect the remaining steering wheel control wire, Key-B or SWC-2, to the Brown/White wire of the connector.
3. If your aftermarket radio has a KEY/SWC Ground wire, leave it disconnected and test your SWC controls.
4. (Optional) If some SWC functions do not program or function correctly, connect the KEY/SWC Ground to the radio’s ground wire.
5. The SWC (Steering Wheel Controls) functions must be programmed within the radio. Refer to Radios with Built-In SWC Menus below.

Programming the Steering Wheel Controller

In order to effectively program the Steering Wheel Controller, the aftermarket radio needs to be (or remain) completely wired. The Steering Wheel Controller harness should be wired and the (Steering Wheel Control) SWC 3.5mm Jack or SWC wiring should be connected.

WARNING Do not plug the Steering Wheel Controller harness into the interface until Step 3 below.

NOTE

If your aftermarket radio is from the Sony XAV Series, before programming to the vehicle, you must:

1. Turn the radio On.

2. From the radio's home screen, click Settings.

3. Click System.

4. In the Steering Wheel Settings section, toggle the Custom switch to Off.

5. Return to the Main Menu.

6. Power Off the radio.

You may now proceed with programming the radio to your vehicle with the steps below.

Follow the steps below to programming the Steering Wheel Controller to your vehicle:

1. Open the driver’s door. Keep it open during the programming process.

2. Turn the vehicle’s ignition On.

3. Plug in the Steering Wheel Controller.

4. The LED on the SWC begins rapid flashing Green and Red.

TIP Once the LED is rapidly flashing, quickly proceed to Step 6.

5. (Optional) If the LED does not turn on, refer to Connections above and ensure all steps were performed precisely.
6. Tap the Volume Up button on the steering wheel at a steady heartbeat pace (1, rest, 2, rest, 3, rest, etc.) until the rapid flash stops (3-5 seconds).

7. (Optional) If the Green and Red flashes are missed, reset the Steering Wheel Controller (as explained below) and restart the programming process from the beginning.
8. Stop tapping the Volume Up button. The Steering Wheel Controller is being programmed into the vehicle’s steering wheel controls (SWC).

NOTE A series of seven (7) Green LED flashes identifies your vehicle type. Once the detection process completes, the Green LED will pause for one to two (1-2) seconds.

TIP Refer to Vehicle LED Feedback below for additional information about Green LED flashes.

9. The LED begins flashing Red while the interface programs itself to the aftermarket radio. A series of up to twenty-four (24) Red LED flashes identifies the detected Radio Type.

TIP Refer to Radio LED Feedback below for radio types.

10. Upon successfully programming, the LED turns solid Red.

11. Test all functions of the Steering Wheel Controller installation for proper operation.

Troubleshooting

1. Verify that 12-volt power and chassis ground have a solid connection.

TIP If a ground wire is attached to the radio harness, remove it and attach it to a bolt or solid piece of metal in the vehicle dash.

2. Verify your connections are correct and that the view of the connector was established properly when locating your connections.
3. Verify the 3.5mm jack is secured in its proper location and not a secondary one.
4. Remove any aftermarket T-taps or barrel connections. These will add resistance to a resistance-based system.
5. If using a 2-wire or 3-wire universal-style radio, verify proper connection to the radio using the female 3.5 jack.
6. (Pioneer radio users) If the radio buttons are not functioning as expected or at all, attempt the following:
1. Insert and remove the 3.5mm male jack in and out of the back of the radio five to six (5-6) times.
2. On the final insertion, ensure the jack is well set.
3. Reset and reprogram the AXSWC.
7. If you’ve established all connections and the AXSWC won’t connect, remove any aftermarket connectors, T-taps, barrel connectors, and quick connectors. These will all add resistance.

WARNING Steering wheel controls must be the ones that came with the vehicle when purchased. Axxess does not support custom work to vehicles, such as adding a new steering wheel with new/different buttons.

→ Radio Troubleshooting

Download General Radio Troubleshooting PDF

AXSWC Radio Troubleshooting - PDF.pdf1420.1KB

If you experience issues programming your Radio, the guides below can help you troubleshoot:

Radio Installations Gallery View (Simple)

Radio Programming Instructions

Radio Programming Instructions

Radio Programming Instructions

Radio Programming Instructions

Radio Programming Instructions

Radio Programming Instructions

NOTE If you’ve exhausted every troubleshooting step offered, contact Technical Support.

Technical Support

TIP If you encounter any difficulties during installation please carefully review the instructions and ensure that the installation was performed exactly as instructed.

Our dedicated team is here to provide you with expert assistance and guidance. Whether you're troubleshooting an installation, seeking product information, or looking for technical advice, we're committed to ensuring your experience with Metra Electronics products is seamless and satisfying.

WARNING Before contacting Metra Technical Support, ensure the vehicle is in a ready state to perform troubleshooting steps.

Contact

Email

(386) 257-1187

Submit a Support Ticket

Vehicle Fit Guide

Hours (EST)

Monday-Friday: 9:00 am - 7:00 pm Saturday: 10:00 am - 5:00 pm Sunday: 10:00 am - 4:00 pm

On this page

• Steering Wheel Controller | Mercedes S-Class | 708
• Vehicle Installation Instructions
• Connections
• Aftermarket Radio Harness
• Vehicle Connection(s) to Factory Harness
• →→ Splicing the Steering Wheel Control Wire to the Connector
• SWC 3.5 Jack Connections
• Kenwood/JVC Radios with Single SWC wire
• → Kenwood & JVC Radio Troubleshooting
• Universal 2-Wire Radios
• Universal 3-Wire Radios
• Programming the Steering Wheel Controller
• Resetting the Steering Wheel Controller
• Radios with Built-In SWC Menus
• LED Feedback
• Changing Radio Type
• Button Remapping
• Dual Assignment Instructions
• Troubleshooting
• → Radio Troubleshooting
• Manual Programming
• Technical Support
• Contact
• Hours (EST)