This procedure covers the removal and replacement of the Battery Thermal Management Module, which regulates battery pack temperature through coolant circulation.

Warnings

Tools required

Parts

• Battery Thermal Management Module × 1 — Use OEM specification
• Thermal management module gasket/seal kit × 1 — Use OEM specification
• Coolant line O-rings × 4 — Use OEM specification
• High-voltage connector seals × 2 — Use OEM specification
• Underbody shield fasteners × 12 — Use OEM specification

Fluids

• EV Battery/Motor Coolant — 10 qt

Preparation

1. Verify vehicle has been parked for minimum 2 hours with no charging activity
2. Place vehicle on level surface and raise on lift to comfortable working height
3. Connect Rivian diagnostic software and document any existing fault codes
4. Remove front and mid-section underbody shields to access battery pack
5. Place coolant drain pans under thermal management module area
6. Don high-voltage safety gloves and verify integrity of insulation
7. Using diagnostic software, command high-voltage system to safe mode
8. Disconnect 12V auxiliary battery negative terminal and wait 5 minutes
9. Open high-voltage service disconnect located in driver-side rear storage compartment
10. Wait 15 minutes for high-voltage capacitors to fully discharge
11. Verify zero voltage at high-voltage disconnect point using rated multimeter
12. Place high-voltage warning tags on service disconnect and steering wheel

Procedure

1. 1

   Drain battery cooling system
   Locate coolant drain valve on the lower side of the battery thermal management module. Attach drain hose to valve and route to drain pan. Using diagnostic software, navigate to Service Functions > Thermal Management > Coolant Drain Mode. This will open internal valves to allow complete drainage. Open drain valve and allow system to drain completely, approximately 8-10 quarts. Once flow stops, close drain valve.
2. 2

   Disconnect thermal management electrical connectors
   Locate the two high-voltage connectors on the thermal management module (pump power and heater power). Press orange safety lock tabs toward connector body and hold. While holding safety lock, pull connector straight back from module. Inspect connector seals for damage and replace if worn. Disconnect three low-voltage connectors (temperature sensors and control module) by pressing release tabs and pulling away from module.
3. 3

   Disconnect inlet coolant line
   Locate the primary coolant inlet line on the front of the thermal management module (larger diameter line, approximately 1.5 inch). Use two wrenches to prevent component rotation: hold module-side fitting stationary while loosening the union nut on the coolant line. Expect residual coolant spillage. Once union nut is free, carefully pull line away from module and cap both openings to prevent contamination. Inspect O-ring in line fitting and replace if damaged.
4. 4

   Disconnect outlet coolant line
   Locate the coolant outlet line on the rear of the thermal management module. Using same two-wrench technique, hold module fitting stationary while loosening outlet line union nut. Remove line and cap both openings. Check for coolant residue or deposits inside fittings that might indicate previous leaks or contamination.
5. 5

   Disconnect secondary coolant lines
   Remove the two smaller diameter coolant lines connected to the integrated heater section of the module. These are typically quick-disconnect style fittings. Press the release collar on each fitting while pulling line straight out. If fittings are corroded or stuck, use approved coolant line disconnect tool. Inspect O-rings in quick-disconnect fittings and replace as part of seal kit.
6. 6

   Remove thermal management module mounting hardware
   Locate six mounting bolts securing the thermal management module to the battery pack housing. These are located around the perimeter of the module flange. Remove bolts in star pattern (opposite corners) to prevent distortion of sealing surfaces. Support module weight during removal of final bolts as unit weighs approximately 35 lbs with integrated components. Note orientation and position of any ground straps or brackets attached to mounting bolts.
7. 7

   Remove thermal management module from battery pack
   With all connections and fasteners removed, carefully lower the thermal management module away from the battery pack. Module may initially stick due to gasket seal. If stuck, gently work around perimeter with plastic pry tool - do NOT use metal tools near battery pack housing. Once free, lower module completely and move to clean work surface. Keep module upright to prevent internal component damage.
8. 8

   Inspect and clean mounting surface
   Inspect battery pack mounting flange where module was installed. Remove all gasket material using plastic scraper - do NOT gouge or scratch aluminum sealing surface. Clean surface with isopropyl alcohol and lint-free cloth. Inspect for cracks, corrosion, or damage around coolant passages and electrical feedthroughs. Check coolant passages in battery pack for debris or blockage. Verify mounting bolt threads in battery pack are clean and undamaged.
9. 9

   Prepare new thermal management module
   Unpack new thermal management module and inspect for shipping damage. Verify part number matches vehicle specification for EDV 500 dual motor configuration. Install new gasket from seal kit onto module flange, ensuring proper alignment with all bolt holes and passages. Apply thin film of EV-approved coolant to gasket to aid installation. Install new O-rings into all coolant line fittings on module, lightly lubricating with coolant. Verify high-voltage connector seals are properly installed and undamaged.
10. 10

    Install thermal management module to battery pack
    Carefully guide thermal management module into position on battery pack, aligning coolant passages and electrical feedthroughs. Ensure gasket remains properly positioned and does not shift. Start all six mounting bolts by hand, threading each 2-3 turns before tightening any. This ensures proper alignment. Following star pattern (opposite corners), gradually tighten mounting bolts in 3 stages to pull module evenly against battery pack without distorting gasket seal. Without specific torque specs, tighten to snug fit plus 1/4 turn.
11. 11

    Reconnect coolant lines
    Connect primary coolant inlet line to module, ensuring O-ring seats properly in fitting. Hand-tighten union nut, then use two-wrench technique to snug fitting without over-tightening aluminum threads. Connect outlet coolant line using same technique. Install secondary coolant lines to heater section, pushing quick-disconnect fittings fully onto module nipples until click is heard/felt indicating lock engagement. Tug each line to verify secure connection.
12. 12

    Reconnect electrical connectors
    Connect three low-voltage connectors (temperature sensors and control module) to thermal management module, ensuring positive lock engagement. For high-voltage connectors, inspect pins for damage or corrosion. Align connector carefully and press firmly onto module terminals until seated. Orange safety lock should snap into locked position automatically - verify lock is fully engaged and cannot be pressed further. Do NOT force connectors.
13. 13

    Refill and bleed cooling system
    Connect coolant vacuum fill tool to fill port on thermal management module per tool manufacturer instructions. Draw vacuum on system to -25 inHg and hold for 5 minutes to verify system integrity - vacuum should not drop more than 2 inHg. With vacuum holding, open valve to coolant supply and allow system to draw in fresh EV Battery/Motor Coolant. Fill until coolant appears in expansion tank at cold fill line. Close fill valve and release vacuum. Using diagnostic software, navigate to Service Functions > Thermal Management > Coolant Purge Cycle. Run automated purge cycle which operates pump at varying speeds to evacuate air from system. Monitor coolant level during purge and top off as needed.
14. 14

    Reinstall underbody shields and restore power
    Install mid-section and front underbody shields using new fasteners where specified. Ensure all shield mounting points are secure and shields do not contact coolant lines. Remove high-voltage warning tags. Reconnect 12V auxiliary battery negative terminal. Close and lock high-voltage service disconnect in rear storage compartment. Remove high-voltage safety gloves.
15. 15

    Commission and test thermal management system
    Connect diagnostic software and navigate to Service Functions > Thermal Management > System Commissioning. Follow on-screen prompts to register new module and initialize control parameters. Clear any fault codes related to thermal management module replacement. Start thermal management system test cycle which runs pump, heater, and monitors temperature sensors. System should run for minimum 10 minutes without faults. Monitor for coolant leaks at all connection points during test cycle. Check coolant level in expansion tank after test - should remain at cold fill line with system at ambient temperature.

Reassembly

1. Install all underbody shields with proper fastener torque to prevent shield vibration
2. Verify all coolant connections are tight and show no signs of seepage
3. Confirm all electrical connectors are fully seated with safety locks engaged
4. Double-check high-voltage service disconnect is properly closed and locked

Verification

• Use diagnostic software to verify no active fault codes in thermal management system
• Confirm all temperature sensors report reasonable ambient temperature readings
• Verify coolant level remains stable in expansion tank after test cycle
• Check that thermal management pump operates smoothly without unusual noise
• Inspect all coolant line connections for leaks while system is under pressure
• Run thermal management self-test cycle and verify all components pass diagnostics
• Perform brief test drive and monitor battery temperature behavior through diagnostic software
• Recheck coolant level after test drive and top off if needed - system should stabilize at cold fill line

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