This procedure covers the removal and replacement of the battery thermal management module, which regulates battery pack temperature through coolant circulation in the 2025 Rivian EDV 500.

Warnings

Tools required

Parts

• Battery Thermal Management Module × 1 — Use OEM specification
• Thermal management module mounting gasket/seal × 1 — Use OEM specification
• Coolant line O-rings × 4 — Use OEM specification
• High-voltage connector seals × 2 — Use OEM specification
• Underbody panel clips × 10 — Use OEM specification

Fluids

• EV Battery/Motor Coolant — 10 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Ensure battery state of charge is below 30% if possible to reduce stored energy
3. Allow battery thermal management system to cool for minimum 2 hours after last operation
4. Disconnect 12V auxiliary battery negative terminal and wait 10 minutes
5. Install high-voltage lockout/tagout device following manufacturer safety procedures
6. Verify high-voltage system is disabled using diagnostic tool (should show HV system offline)
7. Raise vehicle on lift or jack stands to access underbody components
8. Remove driver-side rear underbody access panel (12 plastic clips and 6 Torx fasteners)
9. Place coolant drain pan under battery thermal management module area

Procedure

1. 1

   Verify high-voltage system isolation
   Don high-voltage insulated gloves. Using a calibrated digital multimeter set to DC voltage, measure voltage at the thermal management module high-voltage connector terminals. Verify reading is 0V DC. If any voltage is present, do not proceed until high-voltage system is properly disabled and discharged.
2. 2

   Drain battery cooling system
   Locate the battery coolant drain valve on the underside of the battery pack near the thermal management module. Attach drain hose to valve and route to drain pan. Open drain valve slowly to release system pressure, then fully open to drain coolant. Drain approximately 8-10 quarts of EV Battery/Motor Coolant. Close drain valve when flow stops.
3. 3

   Disconnect low-voltage electrical connectors
   Locate the two low-voltage electrical connectors on the thermal management module: one for temperature sensors (gray 8-pin connector) and one for coolant pump control (black 6-pin connector). Press release tabs and carefully disconnect both connectors. Secure connectors away from work area to prevent contamination.
4. 4

   Disconnect high-voltage connector
   Identify the orange high-voltage connector on the side of the thermal management module. Remove the safety lock by pulling the orange tab straight out. Press the connector release button while pulling the connector straight back from the module. Inspect connector and module terminals for any signs of arcing or damage. Place protective cap over exposed high-voltage terminals on harness side.
5. 5

   Disconnect coolant inlet line
   Locate the coolant inlet line on the front of the thermal management module (marked with blue indicator band). Using appropriate wrench, loosen the quick-disconnect coupling by pressing release tabs while pulling line away from module. Residual coolant will drain - catch with absorbent pads. Cap the open line to prevent contamination.
6. 6

   Disconnect coolant outlet line
   Locate the coolant outlet line on the rear of the thermal management module (marked with red indicator band). Using appropriate wrench, loosen the quick-disconnect coupling by pressing release tabs while pulling line away from module. Allow residual coolant to drain into pan. Cap the open line.
7. 7

   Remove thermal management module mounting fasteners
   Identify the six mounting bolts securing the thermal management module to the battery pack housing (three on each side). Using appropriate socket, remove all six mounting bolts. Keep bolts organized as they may be different lengths. Support the module with one hand while removing final fasteners.
8. 8

   Remove thermal management module
   Carefully lower the thermal management module from the battery pack housing. The module weighs approximately 35 lbs and has coolant passages that may still contain fluid. Tilt module slightly to drain remaining coolant into drain pan as you remove it. Place module on clean work surface. Inspect mounting surface gasket/seal and remove if it remains attached to battery pack.
9. 9

   Clean mounting surfaces
   Thoroughly clean the thermal management module mounting surface on the battery pack housing using lint-free cloths and approved EV coolant system cleaner. Remove all traces of old gasket material, coolant residue, and debris. Inspect mounting surface for damage or corrosion. Surface must be completely clean and dry before installing new module.
10. 10

    Prepare new thermal management module
    Remove new thermal management module from packaging and inspect for shipping damage. Install new O-rings on both coolant inlet and outlet ports - lubricate lightly with fresh EV coolant. Install new mounting gasket/seal onto the module flange, ensuring it seats properly in the gasket groove. Do not use any additional sealants unless specified by Rivian.
11. 11

    Install new thermal management module
    Carefully lift new thermal management module into position on battery pack housing. Align mounting holes and coolant ports with corresponding connections. The module should sit flush against the mounting surface with gasket compressed evenly. Do not force - if alignment is difficult, lower module and reposition.
12. 12

    Install mounting fasteners
    Install all six mounting bolts finger-tight first to ensure proper alignment. Then tighten bolts in a star pattern (alternating sides) to ensure even compression of the mounting gasket. Since specific torque values are not available in the database, tighten bolts gradually and evenly until gasket is fully compressed and module is secure with no movement. Do not overtighten.
13. 13

    Reconnect coolant lines
    Remove caps from coolant inlet and outlet lines. Inspect line quick-disconnect fittings for damage or debris. Connect coolant inlet line (blue band) to front port - push firmly until you hear and feel the connection click and lock. Connect coolant outlet line (red band) to rear port using same technique. Pull on each line to verify secure connection.
14. 14

    Reconnect electrical connectors
    Reconnect low-voltage electrical connectors: temperature sensor connector (gray 8-pin) and coolant pump control connector (black 6-pin). Push each connector until it clicks and locks in place. Install high-voltage connector by aligning keyed connector and pushing straight onto module terminal until fully seated. Install orange safety lock by pushing tab fully in until it clicks. Verify connector is secure and safety lock is engaged.
15. 15

    Refill and bleed cooling system
    Using battery cooling system vacuum fill tool, evacuate air from the system, then refill with fresh EV Battery/Motor Coolant to proper level (approximately 10 quarts total system capacity). Follow vacuum fill tool instructions to ensure complete air removal. Fill coolant reservoir to MAX mark. Close all bleeder valves and reservoir cap. Verify no coolant leaks at connections.

Reassembly

1. Reinstall driver-side rear underbody access panel with all clips and Torx fasteners
2. Verify all underbody panels are secure and properly aligned
3. Reconnect 12V auxiliary battery negative terminal
4. Remove high-voltage lockout/tagout device following proper safety procedures

Verification

• Connect Rivian diagnostic scan tool and enable high-voltage system following tool prompts
• Perform thermal management system initialization and calibration procedure using diagnostic tool
• Clear any diagnostic trouble codes related to thermal management module replacement
• Activate cooling system test mode and verify coolant pump operates and coolant circulates
• Check all coolant line connections for leaks while system is pressurized
• Verify coolant level in reservoir remains stable after running pump
• Monitor battery thermal management module temperatures using diagnostic tool - should show normal sensor readings
• Verify no high-voltage fault codes are present and HV system shows normal operation
• Perform test drive if facility permits - monitor battery temperatures remain within normal range during operation
• Recheck all connections and coolant level after test drive, top off coolant if needed

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