Comfort Roof Control Module for

  • Mercedes Benz SLK (R171)
  • Mercedes Benz CLK (A209)
  • Mercedes Benz SL (R230)

    v3.xx (All Versions)

  • Further information and manuals for all products can be found on our web site

    w w w . m o d s 4 c a r s . c o m

    We explicitly point out that all functions of this control unit should be used only while exercising caution and responsibility. We can NOT be held liable for any damage or injury caused by installing or using this product.
    Important Information. READ BEFORE INSTALLING!
    This manual is designed to produce completely filled pages. In order to get best print results, simply set the borders to minimum settings in the browser's page setup menu and disable headers and footers.

    Activate the print preview and if necessary decrease the zoom level until all pages are shown correctly.

    If you run into any problems after installing the module, please go over the manual again in great detail, clicking every photo for full size!
    We now have a full Knowledge Base with Support Ticket system available online at

    If you need to contact us, the best and fastest way to do so is by opening a support ticket there

    This module comes with our USB Field Upgrade and Configuration Port! We recommend connecting it to a computer BEFORE YOU INSTALL and using our support app "m4cconnect" to do a quick firmware update check. M4cconnect as well as all other information regarding USB update and configuration can be found at You can even configure and activate your favorite module functions and settings on screen before the module is installed in the car! It is a good idea to permanently install the USB cable with the module in the car, leaving the computer plug in an easily accessible spot for later use with a Wifi/3G/4G connected laptop.

    If the top does not work properly or at all after installing the module, these tips can be very helpful:

    1) Turn Function 1 (Main Switch) off (Setting 0). The module will be completely passive. If the problem still persists and the top won't work, check all connections. Please also check the green DATA LED on the module!

    2) Function 2 now has a valet mode (Setting 2) on many modules. Valet mode completely disables opening of the top. Check the setting for function 2 and make sure the module is NOT in valet mode!

    IMPORTANT: Not all modules have the valet mode! Please check the Operation and Programming Manual!

    The DATA LED shows the module status and helps troubleshooting issues during installation:

    When the ignition is ON: The LED should BLINK (flash) in a regular pattern (about 1x per second). This indicates that the module is receiving data and should work OK.

    When the ignition is OFF: The LED should BLINK (flash) as long as the data bus is still active and turn off after a while (max 5 min) indicating that the car has entered stand-by (sleep) mode.

    If the LED is permanently lit with the ignition ON, the module is NOT receiving data from the top controller and all connectors should be checked.

    If the LED does NOT light up at all when turning the ignition ON, the module is either not getting power or not receiving ANY data. All connectors should be checked.
    The red ERROR LED shows problem conditions and helps with troubleshooting during installation.

    LED flashes 1x
  • The module receives data on the CAN input but does not receive a response on the CAN output. The connection between the CAN BUS and the module is OK but the connection between module and top controller (smartTOP) or navigation unit (smartTV) is either interrupted or polarity reversed. Check all plugs ans connections!
    LED flashes 2x
  • For Mercedes modules: The module is receiving unexpected data on the CAN output from a device it expects to be on the CAN input! Very likely the module is connected to the WRONG CAN plug. Instead of just the top controller (smartTOP) or navigation (smartTV) other, unwanted control modules are connected "behind" our module. Undesired operation will be the result! It is important to find the one correct CAN plug!
    LED flashes 3x
  • For Mercedes modules: The device we are trying to control is found on the CAN input instead of the (required) CAN output and hence can not be controlled. The triple blink can be used to quickly identify the correct plug: One by one pull the can plugs until the red LED stops flashing 3x (instead it flashes once), then connect the found plug to the secondary input.
    This module is installed using the 3M wire taps very popular with 12V aftermarket industry for their reliability and durability. The most common problem during installation is a bad contact between the plugs from the supply wires and the wire taps. Please make absolutely sure that the metal blades of the plugs slide into the slots of the t-taps. It happens that the blade "misses" the slot and the connection looks correct, but doesn't make electrical contact!

    The T-taps come in RED (for thin wires), BLUE (for medium wires) and YELLOW (for thick wires).

    To test if you installed the module correctly after all wires are connected, turn the ignition fully on and watch the green LED on the module. It should blink (flash) to signal a correct installation. If the LED either does not turn on or stays on permanently, there is a bad contact or a missing connection! See detailed explanation of the DATA LED.
    The wiring kit for this module uses one or more of the TYCO connectors shown on the left. These are specialty automotive connectors designed for tight and secure electrical connections. In order to avoid reversing polarity, please pay attention to the small numbers embossed in the back of the plugs where the contacts are inserted. In case one of these plugs will need to be removed later, it can be done without any damage to the plastic cap or the crimp contacts. Please see our Knowledge Base article(s) regarding these plugs at
    Installation - Steps 1-3
    1. First, prepare the supplied wiring harness by installing the black connector caps as shown in the white box. Insert the short metal contacts into the smaller cap (left), RED wire in slot 1 and BLACK wire in slot 2. The contact numbers are embossed on the back of the plugs. If polarity is reversed, the module will NOT work! Install the long skinny metal contacts into the larger cap (right), again RED wire in slot 1 and BLACK wire in slot 2. Push the locking tabs down until they snap in place with an audible click.
    Now move the seat all the way back, then firmly grab under the plastic cover with both hands (on the inside) and pull up hard. The cover is held in place by the brackets marked with the red circles.
    For installation on right hand drive cars (UK, Australia etc.), please see RHD steps (10-12) further down!
    2. Two torx screws hold the side panel in place. One on top and one in the middle/side of the panel. Pry out the little oval cover over the one in the middle, then unscrew both of them. Take the side panel out by pushing it outward (left) and down. Pay attention to how it interconnects with the other parts, so you can re-install it correctly later.
    3. Pull up the carpet all the way along the left side. Beneath it there is a black wire harness box. Its cover is held in place by plastic tabs (marked with red circles). Unclip the tabs and pull the plastic cover up.
    Installation - Steps 4-6
    4. A wire harness and two black connection points (terminal blocks) become visible. You will need to work on the one closer to the front of the car, so take it out of its holder and pull it up.
    5. To get the GROUND connection for the module, attach a BLUE T-Tap to one of the PLAIN BROWN wires that go directly to the chassis bolt behind the hood release lever.
    6. To get the permanent +12V connection for the module, attach the RED T-Tap to the THIN PLAIN RED wire in the big wire bundle. If there are several PLAIN RED wires in the bundle, use the thinnest one. Now connect the plugs from the module's wiring harness to both T-Taps, making sure the metal blades of the plugs actually slide INTO the slots of the T-Taps.
    Installation - Steps 7-9
    7. Now the plastic bracket must be removed, before any of the CAN BUS plugs can be pulled out. It is held in place by two tabs on the sides. Push the tabs outward while simultaneously pulling the cover piece upward or stick a screwdriver between the bracket and the terminal block and carefully pry it off. It is a bit tricky to get off, so please be patient and don't use brute force. With the cover gone, the plugs can be removed. The following step explains in detail, how to find the correct plug.
    8. Finding the correct CAN plug - PLEASE WATCH THE VIDEO. Connect the smartTOP module with the module harness (making sure the latch is engaged). Connect the small plug to the CAN bus and tap the unlock button once. Watch the LEDs on the module. Now disconnect the other small plugs one by one (one at a time) until the RED LED on the module stops blinking 3x and instead blinks 1x. The correct plug is now found and can be connected to the matching socket on the module harness. A successful installation is indicated by the GREEN LED blinking.
    9. Place the smartTOP module inside the harness box as shown. Turn ignition on and check the LED on the module. A slow flashing pattern shows that everything is connected correctly. If it stays lit constantly or does not light up at all, check the InstallAID™ section at the beginning of this manual for help. Close the lid and make sure all tabs snap back in place. Replace carpet and side panel. Make sure you snap the side panel in place correctly, as there may be tabs that interconnect with other plastic parts of the dash or the hood release lever cover parts. Replace screws and plastic cover. Installation is complete. IMPORTANT: If an ESP related error message shows up in the display after installation, it will disappear after driving over 20mph.
    Installation for RHD vehicles - Steps 10-12
    10. Installation takes place on the right side of the car, next to the driver's seat and is similar to the left-hand drive models, except that on right-hand drive models there is no 12V power wire in the harness. First remove the panel at the end of the dash (covers the fuses on the RHS end) by levering out with a screwdriver - it's held on by 2 spring clips. Also it is advisable to remove the accelerator pedal by unscrewing a 10mm nut located under a plastic cover. This will greatly simplify lifting the carpet.
    11. Underneath the panel is a wire harness with one plain red wire. This is the power wire to tap with the crimp connector. If you can't get to the wire this way or if the harness is too short, then it is best to carefully remove the light switch as explained in the next step. Taken from Benzworld forums with thanks to chris-h for the writeup!
    12. This exposes a bright blue bracket with a torx 20 screw which holds the light switch unit in place. Unscrew and remove the bracket - it just slots onto the RHS of the light switch unit. On the photo the blue arrow shows where the bracket and screw would be and where it slots into the unit. There are 2 spring clips on the LHS of the unit - one at the top, shown here in magenta and one at the bottom (probably opposite sides for LHD). You can only get to these by unscrewing the 3 Torq 20 screws which hold up the underdash panel. You can then just get your hand up the back of the dash and with the help of a small mirror you should be able to see the spring clips through the open end of the dash - otherwise you should just be able to feel them. Squeeze the top clip in and push the panel out a bit from the inside and then repeat with the bottom clip. Once both clips are free the unit rotates out in the direction of the yellow arrow. To reassemble insert the RHS of the unit first and then clip the LHS in.
    Installation for RHD vehicles - Step 13
    13. Run the supplied power wire from the connection point down the side to the harness box where the smartTOP is located. In this picture a light blue parallel tap was used, in your case please use the supplied RED T-Tap for the permanent +12V power connection. For the GROUND connection use the BLUE T-Tap behind the hood/bonnet release lever, just as described previously for LHD models.
    Installation - Additional Steps
    To allow the module to activate the horn for the CHIRP feature, open the fuse box in the right corner of the engine compartment and reseat the fuse shown from position 43A, left slots (1) to position 43B, right slots (2). This change does not affect anything else.
    NO fuse needs to removed and NO fuse needs to be added. Just RE-SEAT the already existing fuse.