Vehicle and kit scope
The source guide covers 2015–2021 Mercedes-Benz C-Class 205 and GLC 253. This replacement-style installation requires programming/coding to enable the function. Carry a valid vehicle key within operating range and touch an equipped exterior handle's sensor area to lock or unlock the door without pressing a key button. The trunk function is checked separately below.
The general wiring image also names W213; that wider diagram heading does not extend this tutorial's stated vehicle scope. Confirm the vehicle configuration, supplied KG module, handle assemblies and antenna kit before installation.
1. Product components
2. Wiring diagrams
The diagrams show the four door-handle connections, rear-door antennas, KG-module contacts and vehicle-side connector assignments. The kit-side and vehicle-side diagrams use different wire colors; do not treat a color in one diagram as the same circuit in the other without confirming the actual harness. The source does not identify the connector viewing side, module part/version or the door-connector cavity numbers. Obtain that information and the vehicle's electrical isolation procedure before moving terminals or applying power.
3. Installation overview
Remove and refit the door trim panels
The illustrated example uses a T30 driver for the door-panel mounting screws, a plastic trim tool to release the panel clips, and a horizontal pull to release the upper trim retaining tabs. It then shows releasing the outer clip, the interior-handle cable retainer, the midrange-speaker connector and the connection to the door control module. Follow the vehicle-specific removal and refitting procedure: screw locations and tool sizes shown in the example do not establish tightening torques or universal instructions for every vehicle listed.
Replace the exterior handles and route the wiring
The illustrated example uses a T20 driver for the handle retaining screw, replaces the existing handle with a sensor handle and transfers the existing lock cylinder to the replacement assembly. Feed the handle wiring through the shown openings, route it along the existing door harness, and connect the door-side and body-side sections as documented for the supplied kit. The source shows matching male/female terminals in empty door-connector cavities but does not number those cavities. Do not select a cavity solely because it appears empty.
Install the antennas
The source shows an antenna inside a rear door, fixed in the illustrated position with its wiring routed along the existing harness. Connect the door-side and body-side antenna wiring using the exact kit diagram. The troubleshooting text specifies that the antenna should not contact metal.
4. KG module location
The source photograph shows the KG module in a rear cargo-area side compartment. It is an example location, not a verified layout for every body style or equipment configuration.
5. Programming/coding
Programming/coding is required by the source, but no coding list, diagnostic sequence or module pairing procedure is supplied. Obtain the exact vehicle and module procedure before enabling the system; do not substitute the no-programming claim from a different keyless-entry kit.
6. Function checks
- Lock the vehicle and carry its key with you. Touch the trunk switch and check whether the trunk opens.
- At every door fitted with the corresponding sensor handle, touch the sensor area and check locking/unlocking without pressing a key button.
7. Troubleshooting
- Engine does not start after installation: Check whether the KG module was replaced. The source recommends comparison with the original module restored. If normal operation returns, investigate the replacement module; if the fault remains, check the installation and wiring. If no module was replaced, check the installation. The source does not provide the safe module removal or diagnostic procedure.
- Keyless entry does not work: Check the operating trigger, programming/coding, installation and component condition. Carry the active key and check for a second key left inside the vehicle. With a replacement KG module fitted, lock the vehicle using the key and check whether the trunk can open without pressing a key button. If it cannot, check programming/coding and the module. Confirm that the sensor handles were fitted, no connection is open or shorted, and the KG-module contacts correspond to the intended handle and antenna. Use kit-approved comparison procedures to investigate component faults.
- The key works only close to an antenna: Check programming/coding and whether the antenna is touching metal.