This procedure covers the removal, replacement, and calibration of the Battery Management System (BMS) module on the 2023 Rivian EDV 500, including high-voltage isolation and software configuration.

Warnings

Tools required

Parts

• Battery Management System (BMS) module × 1 — Use OEM specification
• High-voltage connector seals (if damaged) × 1 — Use OEM specification
• BMS mounting hardware kit × 1 — Use OEM specification
• Thermal interface pad × 1 — Use OEM specification

Preparation

1. Park vehicle on level ground with parking brake engaged and chock the rear wheels
2. Ensure vehicle is in Park mode and powered off completely
3. Verify high-voltage insulated gloves are tested and within certification date
4. Place high-voltage safety mat under work area
5. Connect Rivian diagnostic laptop and establish communication with vehicle
6. Using diagnostic software, perform BMS data backup and record all configuration parameters
7. Access high-voltage disconnect procedure in diagnostic software and initiate HV system shutdown
8. Open hood and locate high-voltage service disconnect (orange lever) near front of battery pack
9. Wearing HV gloves, pull high-voltage service disconnect and remove to secure location
10. Install lockout/tagout device on service disconnect location
11. Wait minimum 15 minutes for capacitor discharge
12. Using CAT III multimeter with HV gloves, verify 0V across high-voltage bus bars
13. Disconnect 12V negative battery terminal and wait 2 minutes for system de-energization

Procedure

1. 1

   Remove underbody access panel
   Remove the center underbody access panel to access the battery pack and BMS module. Remove twelve T30 Torx screws securing the composite access panel. Carefully lower the panel and set aside in a protected area to prevent damage.
2. 2

   Access BMS module compartment
   Locate the BMS module on the driver's side of the battery pack enclosure, near the center. Remove the protective cover by releasing four T40 Torx screws. Remove the cover and inspect for any coolant leakage or thermal damage around the BMS area.
   ℹ️Take photos of all connector orientations and wire routing before disconnection for reference during reassembly.
3. 3

   Disconnect BMS communication harnesses
   Identify the three CAN bus communication connectors on the BMS module (primary CAN, secondary CAN, and diagnostic CAN). Press the release tabs on each connector and carefully pull straight away from the BMS module. Secure connectors away from work area. Label each connector with tape if not already color-coded.
4. 4

   Disconnect cell voltage sense harnesses
   The BMS has multiple cell voltage sense connectors (typically 8-12 connectors depending on pack configuration). Starting from connector 1, carefully release the locking tab on each connector and disconnect. These are fragile; do not force. Support the harness weight to prevent strain on connectors. Keep connectors in numerical order.
   ⚠Cell sense connectors are extremely fragile. Use gentle pressure only and support harness weight to prevent pin damage.
5. 5

   Disconnect temperature sensor array
   Locate the battery temperature sensor array connector on the side of the BMS module. This is typically a large multi-pin connector with orange or yellow secondary lock. Release the secondary lock by sliding it outward, then press the primary connector release and pull connector straight back from BMS.
6. 6

   Disconnect high-voltage current sensor leads
   Wearing HV gloves and using insulated tools, locate the two high-current sense leads connected to the BMS (typically orange cables with 13mm fasteners). Remove the fastening nuts while supporting the cable lugs. Carefully move cables away from BMS and secure with non-conductive tie. Inspect lugs and connections for corrosion or damage.
   ⚠️Even with HV disconnect removed, treat all orange cables as potentially energized. Verify 0V with multimeter before touching.
7. 7

   Remove BMS coolant lines (if applicable)
   If the BMS module has active cooling, disconnect the coolant quick-connect fittings. Place drain pan underneath to catch residual coolant (approximately 0.5 quarts). Press the release collar on each quick-connect and pull the line straight out. Cap the open coolant lines to prevent contamination.
   ⚠EV coolant may be hot even after vehicle shutdown. Allow cooling period if vehicle was recently operated.
8. 8

   Remove BMS mounting fasteners
   Locate the six mounting bolts securing the BMS module to the battery pack enclosure (typically 10mm hex head bolts). Remove bolts in a crisscross pattern to prevent binding. Keep bolts organized for reinstallation. Note the location of any ground lugs or washers under bolt heads.
9. 9

   Extract BMS module
   Carefully lift the BMS module straight up from the battery pack. The module may have thermal interface material adhering it to a cooling plate. Use gentle rocking motion if needed but do not pry. Once free, place module on ESD-safe mat or surface. Inspect the mounting area for any debris, coolant, or thermal pad remnants.
   ⚠BMS module is sensitive to ESD. Ground yourself and place module on anti-static mat immediately upon removal.
10. 10

    Prepare mounting surface and new BMS
    Clean the BMS mounting surface on the battery pack with isopropyl alcohol. Remove all old thermal interface material using plastic scraper. Ensure surface is clean and dry. Inspect new BMS module for shipping damage. If thermal interface pad is separate, apply it according to manufacturer instructions. Remove any protective films from new BMS connectors.
11. 11

    Install new BMS module
    Carefully align the new BMS module with the mounting holes and thermal interface area. Lower module into position, ensuring thermal pad makes full contact. Start all six mounting bolts by hand to ensure proper thread engagement. Tighten bolts in a crisscross pattern to ensure even seating. Since no torque specification is provided, tighten to snug plus 1/4 turn, checking for proper module seating.
12. 12

    Reconnect high-voltage current sensor leads
    Wearing HV gloves, reconnect the high-current sense leads to the new BMS module. Clean contact surfaces with wire brush if any corrosion is present. Apply thin coat of dielectric grease to lug contact surfaces. Install lugs and secure with fastening nuts. Tighten to snug specification (estimated 15-20 Nm in absence of specification).
13. 13

    Reconnect coolant lines
    If equipped with active cooling, reconnect the coolant quick-connect fittings to the new BMS module. Push each fitting in until a distinct click is heard, then pull back to verify engagement. Wipe away any spilled coolant. Top off coolant reservoir if needed with EV Battery/Motor Coolant to proper level.
14. 14

    Reconnect all BMS harnesses
    Reconnect all harnesses in reverse order of removal: temperature sensor array first, then cell voltage sense connectors in numerical order (1 through final), then the three CAN communication connectors. Ensure each connector clicks fully into place and secondary locks are engaged. Verify no pins are bent or damaged. Route harnesses to match original positions using new zip ties if needed.
15. 15

    Commission and configure new BMS
    With all connections complete but HV service disconnect still removed, reconnect 12V battery. Using Rivian diagnostic software, select BMS replacement procedure. Enter new BMS module serial number when prompted. Upload backed-up configuration data to new module. Perform BMS cell balancing configuration and set pack parameters. Follow all on-screen prompts for initial commissioning. This process typically takes 15-30 minutes.
    ℹ️Do not skip any commissioning steps. Improperly configured BMS can result in inaccurate state-of-charge readings or battery damage.

Reassembly

1. Reinstall BMS protective cover with four T40 Torx screws, ensuring proper seal alignment
2. Reinstall center underbody access panel with twelve T30 Torx screws in crisscross pattern
3. Using diagnostic software, verify all BMS faults are cleared and communication is established
4. Perform final voltage verification across HV bus to confirm 0V before reinstalling service disconnect
5. Wearing HV gloves, reinstall high-voltage service disconnect and ensure it locks into place
6. Remove lockout/tagout device
7. Using diagnostic software, command HV system online and monitor for successful precharge
8. Verify all warning lights extinguish and vehicle enters Ready mode normally

Verification

• Connect diagnostic software and verify BMS reports all cell voltages within normal range (typically 3.0-4.2V per cell)
• Confirm BMS reports accurate pack voltage, current, and temperature readings
• Verify no diagnostic trouble codes (DTCs) are present related to BMS or high-voltage system
• Perform a short test drive (5-10 minutes) and monitor BMS operation through diagnostic software
• Verify state-of-charge (SOC) display is accurate and updates normally during drive
• Check for proper cell balancing initiation (visible in diagnostic software when vehicle is charging)
• Verify no coolant leaks around BMS module if liquid-cooled
• Confirm charging system operates normally and BMS controls charging current appropriately
• Perform final inspection of all underbody panels for proper installation and clearance

More procedures for this vehicle