Electronic Parking Brake Motor

This procedure replaces the electronic parking brake motor on the rear brake calipers of a 2025 Rivian EDV 500, restoring proper parking brake function.

Warnings

Tools required

Parts

• Electronic parking brake motor × 1 — Use OEM Rivian specification
• EPB motor mounting bolts (if corroded) × 2 — Use OEM specification
• Copper anti-seize paste × 1 — Use high-temperature brake compound

Fluids

• DOT 4 Brake Fluid — 0.25 qt

Preparation

1. Park vehicle on level ground and ensure transmission is in Park
2. Place wheel chocks in front of front wheels
3. Connect Rivian diagnostic tool and verify communication with vehicle systems
4. Using diagnostic software, retract electronic parking brake to service position (this moves the caliper piston fully inward)
5. Open hood and locate 12V battery in front compartment
6. Disconnect negative terminal of 12V battery and wait 5 minutes for system capacitors to discharge
7. Install battery disconnect lockout device if available
8. Loosen rear wheel lug nuts while vehicle is on ground
9. Raise rear of vehicle using jack at designated lifting points per owner's manual
10. Secure vehicle on jack stands rated for commercial vehicle weight (EDV 500 exceeds 7,000 lbs)
11. Remove rear wheel on side requiring EPB motor replacement

Procedure

1. 1

   Access the rear brake caliper
   Locate the rear brake caliper assembly. The electronic parking brake motor is mounted on the inboard side of the caliper, visible from behind the rotor. Note the orientation and routing of the electrical connector before disassembly.
2. 2

   Disconnect EPB motor electrical connector
   Locate the electrical connector on the EPB motor. Press the locking tab and pull the connector straight away from the motor. If the connector is corroded or stuck, spray with electrical contact cleaner and gently wiggle while pulling. Do not pull on the wires themselves.
3. 3

   Remove EPB motor protective cover
   If equipped, remove the rubber or plastic protective cover from the EPB motor assembly by pulling it straight off. This may require rotating slightly to clear retaining tabs. Inspect for debris or moisture intrusion.
4. 4

   Remove EPB motor mounting bolts
   Using a Torx T30 or T40 driver (verify size before applying force), remove the two bolts securing the EPB motor to the rear of the brake caliper. Support the motor as you remove the final bolt to prevent it from falling. These bolts typically have thread-locking compound applied.
5. 5

   Extract the EPB motor from caliper
   Carefully pull the EPB motor straight out from the caliper housing. The motor shaft engages with the caliper piston mechanism and may require slight rotation while pulling. If resistance is encountered, verify the brake was properly retracted in the preparation steps. Do not use excessive force.
6. 6

   Inspect caliper piston mechanism
   With the motor removed, inspect the threaded spindle mechanism inside the caliper for damage, corrosion, or debris. The spindle should rotate freely by hand. Clean with brake cleaner and wire brush if contamination is present. If the spindle is damaged or seized, the entire caliper requires replacement.
7. 7

   Prepare new EPB motor
   Remove the new EPB motor from packaging. Verify it matches the original part number and configuration. Inspect the motor shaft for the correct thread direction and engagement teeth. Apply a thin coating of copper anti-seize compound to the motor shaft threads, avoiding the electrical components.
8. 8

   Install new EPB motor
   Align the new EPB motor with the caliper housing, ensuring the shaft threads engage properly with the spindle mechanism. Slowly rotate the motor clockwise while applying gentle inward pressure until it seats fully against the caliper. The motor should slide in smoothly without binding.
9. 9

   Install EPB motor mounting bolts
   Install the two mounting bolts and hand-tighten. Apply medium-strength thread locker (blue) to the bolt threads if not pre-applied. Tighten bolts in a cross pattern to ensure even seating. Without manufacturer torque specifications, tighten to 15-18 ft-lbs using a calibrated torque wrench. Over-tightening can crack the motor housing.
10. 10

    Reconnect electrical connector
    Reconnect the electrical connector to the EPB motor, ensuring it clicks fully into place. Gently pull on the connector (not wires) to verify it is locked. Reinstall the protective cover if equipped, ensuring weather seals are properly seated.
11. 11

    Reinstall wheel and lower vehicle
    Reinstall the rear wheel, hand-tightening lug nuts in a star pattern. Lower vehicle from jack stands to ground. With vehicle weight on wheels, torque lug nuts to manufacturer specification (typically 130-140 ft-lbs for EDV 500) in star pattern.
12. 12

    Reconnect 12V battery
    Reconnect the negative terminal of the 12V battery. Ensure connection is tight and corrosion-free. The vehicle will perform self-checks upon powering up.
13. 13

    Calibrate EPB system with diagnostic tool
    Connect Rivian diagnostic tool and access EPB calibration function. Follow on-screen prompts to perform EPB motor calibration. This process typically involves automated engage/release cycles. The calibration must complete successfully before the vehicle is safe to drive. If calibration fails, verify all connections and repeat procedure.
14. 14

    Test EPB function
    With vehicle in Park on level ground and foot off brake pedal, manually activate parking brake using dash button or switch. Listen for EPB motor operation and verify brake engages (check indicator on dash). Deactivate parking brake and verify release. Repeat 3-5 times to ensure consistent operation.

Reassembly

1. Ensure all electrical connectors are fully seated with locking tabs engaged
2. Verify EPB motor mounting bolts are torqued evenly and motor sits flush against caliper
3. Confirm no tools or parts were left in wheel well or under vehicle
4. Check brake fluid level in master cylinder reservoir and top off with DOT 4 fluid if needed (fluid level should not drop significantly during this procedure)

Verification

• Start vehicle and verify no brake system warning lights remain illuminated on dash
• With vehicle in Park, engage parking brake and attempt to push vehicle - it should not roll
• Disengage parking brake and verify release indicator shows on dash
• Perform test drive in safe area at low speed (under 10 mph), testing service brakes for normal operation
• On slight incline, engage parking brake and verify vehicle remains stationary when transmission is shifted to Neutral
• Using diagnostic tool, check for any EPB-related fault codes and verify calibration success
• If any abnormal operation is detected (noise, incomplete engagement, warning lights), do not operate vehicle and consult Rivian service

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

Chasing one of these codes and not sure which part is guilty? Ask a master mechanic about YOUR car →

More procedures for this vehicle