Parking Brake Actuator

Replacement of an electric parking brake (EPB) actuator on a 2024 Model 3 Long Range rear caliper. The EPB is integrated into each rear caliper as a motor-on-caliper unit; this job requires retracting the actuator electronically before mechanical removal.

Warnings

Tools required

Parts

• Rear parking brake actuator (motor-on-caliper EPB module) × 1 — Tesla Model 3 rear EPB actuator — match side (LH/RH) per VIN
• Actuator-to-caliper O-ring/seal (if supplied separately) × 1 — OEM seal kit for EPB actuator
• Actuator mounting bolts (if single-use) × 3 — OEM specification

Preparation

1. Park on level ground, place in P, engage parking brake.
2. Exit ALL doors with the key fob away from the vehicle. Wait at least 2 minutes for HV systems to fully de-energize, even on this non-HV job.
3. Before disconnecting 12V: use a Tesla-compatible diagnostic tool to place the EPB into 'service' / 'release' mode so the actuator fully retracts the parking brake mechanism. Confirm both rear EPBs are released.
4. Disconnect the low-voltage battery. On 2024 Model 3, the 12V (Li-ion) battery is typically located under the rear floor area or behind the right rear seat back panel — refer to architecture notes and verify location on this specific build before removing trim.
5. DO NOT touch, cut, or pierce ANY orange cable — these are high-voltage and lethal. If you encounter an orange cable, an HV component, or are unsure if a system is de-energized: STOP and consult a Tesla-certified technician.
6. Loosen rear wheel lug nuts while vehicle is on the ground.
7. Raise the rear of the vehicle using only Tesla-approved lift points with proper puck adapters. Support on jack stands rated for EV curb weight.
8. Remove the affected rear wheel(s).
9. Inspect the caliper area for any wiring routed near orange HV cabling from the rear drive unit; route service work clear of HV harnesses.

Procedure

1. 1

   Confirm EPB is fully released
   Visually verify the actuator is in the retracted/service position. The actuator output shaft should not be loading the caliper piston. If the EPB was not commanded to service mode prior to 12V disconnect, reconnect 12V, command release with a scan tool, then disconnect 12V again. Do not proceed with the actuator under load.
   ⚠️Removing a loaded EPB actuator can launch internal components and damage the caliper.
2. 2

   Disconnect actuator electrical connector
   Locate the EPB actuator on the rear of the caliper. Release the connector lock tab and unplug the wiring harness from the actuator. Inspect the connector pins for corrosion or water intrusion — a common cause of EPB faults on Model 3. Move the harness aside and secure it so it is not strained during actuator removal.
3. 3

   Free the harness from caliper retainers
   Release the EPB harness from any caliper-mounted clips or P-clamps so the harness will not be damaged when the actuator is rotated off the caliper. Note routing for reassembly.
4. 4

   Remove the EPB actuator from the caliper
   Remove the actuator-to-caliper fasteners (typically three Torx-head bolts arranged around the actuator housing). Support the actuator as the last fastener is removed. Pull the actuator straight off the caliper — do not pry against the aluminum caliper casting. Catch and discard the seal/O-ring between the actuator and caliper.
   ⚠The actuator drive coupling may stay on the caliper or come off with the actuator. Note its orientation for reinstallation.
5. 5

   Inspect caliper bore and drive coupling
   Inspect the caliper-side drive interface, threaded spindle, and bore for corrosion, debris, or moisture. Wipe clean with a lint-free cloth. Do not introduce solvent into the caliper bore. If the spindle shows damage or the piston does not rotate freely, the caliper itself must be replaced — a new actuator alone will not resolve the fault.
6. 6

   Install new actuator seal
   Install the new O-ring/seal supplied with the replacement actuator into the correct groove. Confirm the seal is fully seated and not twisted. A pinched seal will cause moisture intrusion and premature failure.
7. 7

   Install the new EPB actuator
   Align the new actuator's drive coupling with the caliper spindle. Hand-seat the actuator squarely against the caliper — it should drop fully home with no gap before fasteners are started. If it will not seat, rotate the drive coupling slightly to engage the spindle splines. Do not draw the actuator down with the bolts.
   ⚠Forcing the actuator down with the bolts will crack the housing or strip the caliper threads.
   Torque spec

   Mounting Bolts27 Nm (20 lb-ft)
8. 8

   Torque actuator mounting fasteners
   Install the three actuator mounting bolts and torque in a cross/star pattern to the Mounting Bolts specification. If the bolts are specified as single-use by the manufacturer, use new bolts.
   Torque spec

   Mounting Bolts27 Nm (20 lb-ft)
9. 9

   Reconnect harness and re-secure routing
   Reconnect the electrical connector until the lock tab clicks. Reinstall the harness into all original retainers and clips. Verify clearance from the rotor, suspension links, and any nearby HV cabling — the harness must not contact moving or hot components.

Reassembly

1. Reinstall the rear wheel. Hand-thread all lug nuts before applying torque.
2. Lower the vehicle to the ground.
3. Torque wheel lug nuts in a star pattern to the Wheel Lug Nuts specification.
4. Reconnect the 12V low-voltage battery. Reinstall any trim removed for battery access.
5. Allow the vehicle to power up fully; expect dash warnings related to EPB, traction systems, and possibly TPMS until calibration is complete.

Verification

• Using a Tesla-compatible diagnostic tool, exit EPB service mode and command an EPB calibration / apply-release cycle. Confirm no DTCs remain for the rear EPB actuator (open circuit, position sensor, motor stall).
• With the vehicle safely supported or on a level surface, cycle the parking brake from the touchscreen multiple times. Listen for smooth, even actuation on both rear corners — a healthy actuator makes a brief, consistent motor whir.
• Perform a low-speed roll test in a safe area: confirm the parking brake holds the vehicle stationary on a slight incline and releases cleanly when shifted to D or R.
• Recheck the wheel lug torque after a short drive to the Wheel Lug Nuts specification.
• Note: if brake fluid was disturbed or the system was opened during diagnosis, follow Tesla's 2-year brake fluid replacement recommendation and bleed/refresh as required (this job alone does not normally open the hydraulic circuit).

Related trouble codes on this vehicle

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