Rear Left-Hand (LH) Door Latch for 2023+ Tesla Model 3 | 1738948-01-D (CFN Brand)

Core Functions

1. Secure Door Locking & Unlocking
   Syncs with the Model 3’s central locking system (via BCM, Body Control Module) to execute locking/unlocking commands—whether triggered by the key fob, in-car touchscreen, or exterior door handle. When locked, it engages a stainless steel striker pin (mounted on the door pillar) to prevent accidental door opening during driving; when unlocked, it releases the striker smoothly to ensure easy door access.
2. Reliable Opening/Closing Control
   Features a precision mechanical linkage and electronic solenoid that coordinate with the interior/exterior door handles. When the exterior handle is pressed (or interior handle pulled), the latch’s solenoid activates to disengage the locking mechanism, allowing the door to open without jamming. It also includes a “half-latch” function—if the door is not fully closed, the latch catches the striker temporarily (preventing the door from swinging open) and triggers a dashboard warning to remind the driver.
3. Safety Compliance & Emergency Protection
   Meets Tesla’s safety standards for crash and emergency scenarios:

• Crash Locking: Automatically locks the door during a collision to prevent door ejection;
• Emergency Release: Retains a manual mechanical release (accessible via the rear door’s emergency pull tab) to allow door opening if the electrical system fails;
• Child Safety Lock Compatibility: Works with the rear door’s child safety lock (manual toggle) to disable the interior handle, preventing accidental opening by children.

Durable Construction & Technical Features

• Mechanical Structure: The main latch body is made of glass-fiber reinforced PA66 plastic (tensile strength ≥80MPa) for impact resistance; critical moving parts (e.g., locking pawl, ratchet) use hardened steel (hardness ≥HRC 50) to reduce wear—ensuring a service life of over 50,000 opening/closing cycles.
• Electronic Components: The built-in solenoid uses copper-wound coils (insulation class B, withstands 130°C) for stable electrical performance; the position sensor (to detect door status: locked/unlocked/half-closed) uses a Hall-effect chip with high accuracy (error ≤1%), ensuring real-time feedback to the BCM.
• Environmental Resistance: Sealed with IP6K7-rated rubber gaskets to prevent water, dust, or car wash chemicals from entering the internal mechanism—avoiding rust or short circuits. It also withstands temperature fluctuations (-40°C to 85°C), suitable for extreme climates.

Installation 要点

1. Vehicle Preparation: Ensure the vehicle is powered off; open the rear left door and remove the inner door panel (use a trim tool to detach plastic clips, then disconnect the window switch wiring harness and door handle cables).
2. Old Latch Removal: Locate the old latch (mounted on the door’s inner metal frame, secured by 3 x 10mm bolts). Disconnect the electrical connector (for solenoid and sensor) and the mechanical cables (linked to interior/exterior handles). Use a 10mm socket to remove the 3 bolts, then pull the old latch away from the door frame.
3. Cleaning & Inspection: Wipe the door frame’s latch mounting surface with a dry cloth; check the striker pin (on the door pillar) for looseness or deformation—tighten or replace if needed.
4. New Latch Installation: Align 1738948-01-D with the door frame’s mounting holes; reconnect the electrical connector and mechanical cables (ensure cables are not twisted). Hand-tighten the 3 x 10mm bolts to avoid cross-threading.
5. Torque Fastening: Use a torque wrench to tighten the bolts to 8±0.5 Nm (per Tesla’s 2023+ Model 3 service specs)—over-tightening may crack the latch’s plastic body.
6. Function Testing: Reinstall the inner door panel and power on the vehicle. Test:
   • Lock/unlock via key fob and touchscreen;
   • Open/close the door to confirm smooth operation (no jamming);
   • Check the dashboard for door status feedback (e.g., “Rear Left Door Open” warning if not closed fully);
   • Activate the child safety lock to verify interior handle disablement.

Note: This part is rear left-hand (LH) specific—do not interchange with front door latches or rear right-hand (RH) latches (e.g., 1738949-01-D). After installation, clear any BCM error codes (using a Tesla diagnostic tool) to ensure the latch communicates normally with the vehicle’s electrical system.