This procedure covers the replacement or repair of the Battery Management System (BMS) module on the 2025 Rivian EDV 500, including high-voltage safety procedures, BMS removal, installation, and system calibration.

Warnings

Tools required

Parts

• Battery Management System (BMS) module × 1 — Use OEM specification
• High-voltage connector seals × 4 — Use OEM specification
• BMS thermal interface pad × 1 — Use OEM specification
• High-voltage warning labels × 2 — Use OEM specification

Preparation

1. Park vehicle on level ground and engage parking brake
2. Ensure vehicle is in Park mode and powered off completely
3. Connect a 12V battery maintainer to the low-voltage battery to maintain vehicle systems
4. Allow battery pack to reach ambient temperature if vehicle was recently charged or driven (wait minimum 2 hours)
5. Put on high-voltage insulated gloves and verify glove integrity
6. Place high-voltage warning signs around the vehicle work area
7. Locate and review the vehicle's high-voltage system schematic in service documentation
8. Ensure fire extinguisher rated for electrical fires (Class C) is readily accessible

Procedure

1. 1

   Disconnect 12V battery
   Disconnect the negative terminal of the 12V battery, then disconnect the positive terminal. Wait 5 minutes for vehicle systems to fully power down. Ensure the 12V maintainer is connected only after both terminals are disconnected to preserve system memory.
2. 2

   Access high-voltage disconnect
   Remove the rear cargo area floor panels to access the high-voltage service disconnect. On the EDV 500, this is located in the rear left corner of the cargo area beneath the floor panel. Remove the orange high-voltage service disconnect cover.
3. 3

   Disable high-voltage system
   Pull the high-voltage service disconnect lever to the OFF position and rotate 90 degrees. Remove the service disconnect plug completely and store it in your pocket or secure location away from the vehicle. Place the insulating safety lock in the disconnect receptacle.
4. 4

   Wait for capacitor discharge
   Wait a minimum of 15 minutes for all high-voltage capacitors to discharge. Set a timer to ensure full compliance. Do not proceed until the full time has elapsed.
5. 5

   Verify zero voltage
   Using a calibrated 1000V-rated multimeter, verify zero voltage at the high-voltage service disconnect points. Measure between positive and negative terminals, then from each terminal to chassis ground. All readings must be below 5V DC. Document voltage readings.
6. 6

   Remove underbody access panel
   Raise vehicle on lift or support safely on jack stands. Remove the underbody aerodynamic panels beneath the battery pack to access the BMS location. The BMS is mounted on the front driver-side corner of the battery pack enclosure. Remove plastic fasteners and set panels aside.
7. 7

   Disconnect BMS electrical connections
   Locate the BMS module on the battery pack. Disconnect the low-voltage communication harness connector (gray connector) from the BMS. Press the release tab and pull straight out. Disconnect the high-voltage sense wire connectors (orange connectors, 4 total) by unlocking the secondary lock tabs and carefully separating each connector.
8. 8

   Document BMS configuration
   Before removing the BMS, connect the diagnostic tool to the vehicle's OBD-II port. Power up the diagnostic tool and retrieve the current BMS configuration data, including battery pack serial number, cell configuration, and calibration parameters. Save this data to external storage device for transfer to new BMS.
9. 9

   Disconnect coolant lines (if equipped)
   If the BMS module on this configuration has integrated coolant cooling, place drain pan beneath connections. Using appropriate disconnect tool, separate the quick-connect coolant lines from the BMS module. Expect approximately 1-2 quarts of EV Battery/Motor Coolant to drain. Cap open coolant lines immediately to prevent contamination.
10. 10

    Remove BMS mounting hardware
    Remove the BMS module mounting bolts securing the unit to the battery pack enclosure. There are typically 6 mounting bolts. Support the BMS module while removing the final bolts to prevent it from falling. Carefully lower the BMS module, being mindful of any remaining connections or routing.
11. 11

    Install new BMS module
    Apply new thermal interface pad to the mounting surface if thermal management is integrated into the design. Position the new BMS module onto the battery pack enclosure, aligning mounting holes. Install all mounting bolts and tighten in a star pattern. Since no torque specifications are provided in the database, follow manufacturer specifications from the service manual or replacement part documentation.
12. 12

    Reconnect coolant lines (if equipped)
    Install new O-ring seals on coolant quick-connect fittings. Reconnect coolant lines to the BMS module, ensuring they click fully into place. Tug gently on each line to verify secure connection. The cooling system will be bled during final verification steps.
13. 13

    Reconnect electrical connections
    Install new high-voltage connector seals on the orange high-voltage sense wire connectors. Reconnect all four high-voltage sense wire connectors to the BMS module, ensuring secondary locks engage fully. Reconnect the gray low-voltage communication harness connector until it clicks into place. Verify all connections are fully seated and locked.
14. 14

    Transfer BMS configuration
    With the diagnostic tool still connected, power up the vehicle systems using the 12V maintainer. Access the BMS programming function and transfer the saved configuration data to the new BMS module. Program the new BMS with the battery pack serial number and cell configuration. This process typically takes 10-15 minutes.
15. 15

    Reinstall underbody panels and reconnect high-voltage system
    Reinstall all underbody aerodynamic panels and secure with fasteners. Lower vehicle from lift. In the rear cargo area, remove the insulating safety lock from the high-voltage disconnect receptacle. Reinstall the high-voltage service disconnect plug, rotate to locked position, and push lever to ON position. Replace the orange high-voltage service disconnect cover.

Reassembly

1. Reinstall all cargo area floor panels and ensure proper fit
2. Apply new high-voltage warning labels near the BMS location if originals were damaged during removal
3. Reconnect the 12V battery: positive terminal first, then negative terminal
4. Remove 12V battery maintainer
5. Verify all tools and parts have been removed from vehicle and surrounding area

Verification

• Connect diagnostic tool and clear any fault codes related to BMS replacement procedure
• Perform BMS initialization sequence using diagnostic tool (follow tool-specific prompts)
• Verify all battery cell voltages are being reported by the new BMS and are within 0.1V of each other
• Check for any high-voltage isolation faults - all readings should show proper isolation resistance (>100 megaohms)
• Start vehicle and verify all dashboard indicators are normal, with no high-voltage system warnings
• Perform a controlled charge cycle to 20-30% SOC and monitor BMS data: verify proper cell balancing operation, temperature monitoring of all sensors, and current sensing accuracy
• If coolant lines were disconnected, bleed the EV cooling system according to manufacturer procedure and verify coolant level is correct (10.00 qt total system capacity)
• Perform a brief test drive (5-10 minutes) in a safe area, monitoring BMS data for any anomalies in voltage, current, or temperature readings
• After test drive, use thermal imaging camera if available to verify even temperature distribution across battery pack
• Perform final fault code scan - verify no active or pending codes related to BMS or high-voltage system
• Document final cell voltages, BMS software version, and configuration date in vehicle service records

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