LED Headlight Module

This procedure covers the removal and replacement of the LED headlight module assembly on a 2019 Mercedes-Benz G-Class with 4.0L Turbo V8 engine.

Warnings

Tools required

Parts

• LED headlight module assembly × 1 — A4638200461 (left) or A4638200561 (right)
• Headlight mounting seal/gasket (if damaged) × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake
2. Turn off ignition and remove key from vehicle
3. Disconnect negative battery terminal and wait 5 minutes for system capacitors to discharge
4. Place fender cover or soft cloth over the fender edge to protect paint during work
5. Open hood and secure in open position

Procedure

1. 1

   Access the headlight module
   Locate the headlight assembly at the front of the vehicle. On the G-Class (W463 II), the round LED headlamp is accessed from the front; the adjacent fender-mounted turn signal/indicator unit is removed first to access certain mounting fasteners. Verify the exact access method against the WIS/AR procedure for this platform before proceeding.
2. 2

   Disconnect electrical connectors
   Locate the main headlight electrical connector at the rear of the module. Press the locking tab and pull the connector straight back to disconnect. There is a secondary connector for the headlight leveling motor - disconnect this by pressing the release tab and pulling away. Note the routing of the wiring harness for reinstallation.
3. 3

   Remove headlight module cover screws
   If the module has a rear access cover or dust cap, remove its retaining screws. Verify the exact fastener count and Torx/driver size against the WIS/AR procedure for this platform before proceeding, as many sealed LED modules have no serviceable rear cover.
4. 4

   Remove upper mounting bolt
   Locate the upper headlight module mounting bolt at the top of the assembly. Use the correct socket to remove this bolt completely. Verify the torque specification against the WIS/AR procedure for this platform before reinstallation; headlight housing bolts are typically low-torque (approximately 7-9 Nm), not 39 Nm. Support the headlight module with one hand as you remove the last mounting bolt.
   ⚠Support the headlight module before removing the final mounting bolt to prevent it from falling and causing damage.
5. 5

   Remove side mounting bolts
   Remove the side mounting bolts securing the headlight module to the body structure. Verify the exact bolt count and torque specification against the WIS/AR procedure for this platform; headlight housing bolts are typically low-torque (approximately 7-9 Nm), not 31 Nm.
6. 6

   Disengage lower retention clip
   At the bottom of the headlight module, locate the lower retention clip or pin. This may be a push-pin style fastener or a spring clip. Press the center or squeeze the tabs (depending on type) and pull forward to release the lower mounting point.
7. 7

   Remove headlight module from vehicle
   With all mounting points released, carefully pull the headlight module forward and out of the vehicle. The module will slide forward on alignment pins. Angle the assembly as needed to clear the fender and hood structures. Inspect the mounting gasket/seal for damage - replace if torn or compressed.
8. 8

   Prepare new LED headlight module
   Remove the new LED headlight module from protective packaging. Verify the part number matches the old module and is correct for the side being replaced (left vs right). Install new mounting gasket/seal onto the new module if provided separately. Do not remove any protective films from the lens until installation is complete.
9. 9

   Install new headlight module
   Carefully guide the new headlight module into position, aligning the mounting pins with their corresponding holes in the body structure. Angle the assembly as needed to clear the fender and hood. Push the module rearward until it seats fully against the body panel. The alignment pins should center the module automatically.
10. 10

    Secure lower retention clip
    Engage the lower retention clip or pin first to stabilize the module. Push the clip firmly into place until it clicks or seats fully.
11. 11

    Install side and upper mounting bolts
    Install the 2 side mounting bolts and hand-tighten. Install the upper mounting bolt and hand-tighten. Once all bolts are started, torque them evenly to the value specified in the WIS/AR procedure for this platform (headlight housing bolts are typically low-torque, approximately 7-9 Nm). Do not overtighten, as excessive torque can crack the plastic housing.
12. 12

    Reconnect electrical connectors
    Reconnect the main headlight electrical connector, pushing firmly until the locking tab clicks into place. Reconnect the leveling motor connector, ensuring it clicks and locks securely. Route the wiring harness as noted during removal, ensuring no pinch points or interference with moving components.
13. 13

    Install rear access cover
    Position the rear access cover or dust cap onto the headlight module. Install the access cover screws and tighten to the specification in the WIS/AR procedure (dust-cap/cover screws are typically hand-snug or low torque, well under 12 Nm). Ensure the seal is properly seated to maintain weatherproofing. Ensure the seal is properly seated to maintain weatherproofing.
14. 14

    Reconnect battery and test operation
    Reconnect the negative battery terminal. Turn the ignition to the ON position (engine does not need to start). Test all headlight functions: low beam, high beam, daytime running lights, turn signals, and adaptive headlight movement if equipped. Verify the headlight leveling system initializes properly. Check for any warning messages on the instrument cluster.

Reassembly

1. Remove all protective films from the headlight lens only after successful installation and testing
2. If headlight aim is incorrect or warning messages appear, the vehicle may require dealer-level diagnostics to perform headlight calibration and coding procedures
3. Clean any fingerprints or debris from the headlight lens using a microfiber cloth and appropriate cleaner

Verification

• Verify all headlight functions operate correctly: low beam, high beam, DRL, turn signals
• Check that adaptive headlight system (if equipped) sweeps properly when turning the steering wheel with ignition on
• Confirm no warning messages appear on the instrument cluster related to headlight malfunction
• Inspect around the headlight module for proper seating and alignment with body panels - gaps should be even
• Verify no moisture or condensation appears inside the headlight module after testing
• Perform a test drive in darkness to confirm proper light output and pattern
• If headlight aim appears incorrect, headlight aiming adjustment or dealer calibration may be required

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