Battery Cooling System Service

Service the battery cooling system including coolant replacement, inspection of cooling lines, pump verification, and system pressure testing to ensure optimal thermal management of the high-voltage battery pack.

Warnings

Tools required

Parts

• Battery cooling system O-rings × 1 — Use OEM specification
• Underbody shield fasteners × 1 — Use OEM specification
• Coolant reservoir cap × 1 — Replace if damaged

Fluids

• EV Battery/Motor Coolant — 10 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Ensure vehicle has been off for at least 2 hours to allow cooling system to reach ambient temperature
3. Verify battery state of charge is below 80% for safety
4. Power down vehicle completely using infotainment screen shutdown procedure
5. Disconnect 12V auxiliary battery negative terminal and wait 5 minutes
6. Place high-voltage warning tags on steering wheel
7. Raise vehicle on lift to working height and secure with jack stands
8. Remove underbody aerodynamic shields to access battery cooling components

Procedure

1. 1

   Verify high-voltage system isolation
   Using a high-voltage rated multimeter, verify that the high-voltage battery system is fully de-energized. Measure voltage at the HV service disconnect location. Voltage must read less than 5V DC. Document the reading. Ensure high-voltage safety gloves are worn throughout the procedure.
2. 2

   Connect diagnostic tool
   Connect the Rivian diagnostic tool to the vehicle's OBD-II port. Select the battery cooling system service procedure. Record any diagnostic trouble codes related to the cooling system before beginning work. Print or save these codes for reference.
3. 3

   Locate and access coolant drain point
   From underneath the vehicle, locate the battery cooling system drain valve on the lowest point of the battery pack cooling circuit. This is typically on the driver's side of the battery enclosure. Position a drain pan with at least 15 quart capacity directly beneath the drain valve.
4. 4

   Drain battery coolant
   Open the battery coolant drain valve slowly to control flow rate. Allow coolant to drain completely, which may take 15-20 minutes. Once flow stops, use the diagnostic tool to activate the battery cooling pump in purge mode for 30 seconds to evacuate remaining coolant. Close drain valve after all coolant has been collected. Inspect drained coolant for contamination, debris, or discoloration indicating system degradation.
5. 5

   Remove coolant reservoir
   Locate the battery coolant reservoir in the front compartment area. Disconnect the electrical connector from the coolant level sensor. Remove the coolant hoses from the reservoir using appropriate disconnect tools. Remove mounting fasteners and extract the reservoir. Inspect reservoir interior for sediment or contamination.
6. 6

   Inspect cooling lines and connections
   Thoroughly inspect all visible battery cooling lines, especially at connection points and along the battery pack perimeter. Look for signs of leakage (white residue), cracking, chafing, or damage. Check quick-disconnect fittings for proper engagement and seal condition. Inspect the battery chiller unit connections and heat exchanger interfaces.
7. 7

   Replace O-rings and seals
   At each coolant line connection point accessed during this service, remove and replace O-rings with new OEM parts. Lightly lubricate new O-rings with fresh battery coolant before installation. Ensure O-ring grooves are clean and free of debris. Pay particular attention to connections at the battery pack inlet/outlet and chiller unit.
8. 8

   Clean and reinstall coolant reservoir
   Thoroughly clean the coolant reservoir with water and mild detergent if reusing. If contamination was found, replace with new reservoir. Install reservoir with new mounting hardware, reconnect coolant hoses ensuring positive engagement of quick-connect fittings, and reconnect the level sensor electrical connector.
9. 9

   Perform vacuum fill procedure
   Connect the coolant vacuum fill tool to the battery cooling system fill port. Create a vacuum of at least 20 inHg and hold for 5 minutes to check for leaks. If vacuum holds, introduce fresh EV Battery/Motor Coolant through the vacuum fill tool. The vacuum will draw coolant into the system. Fill until coolant reaches the appropriate level in the reservoir (typically to the MAX cold fill line). This process ensures no air pockets remain in the system.
10. 10

    Bleed cooling system using diagnostic tool
    With the diagnostic tool still connected, reconnect the 12V battery negative terminal. Power up the vehicle to accessory mode. Using the diagnostic tool, initiate the battery cooling system bleed procedure. This will cycle the cooling pump through specific patterns to purge air from the system. Monitor coolant level in reservoir and add coolant as needed during this process. The bleed cycle typically takes 10-15 minutes.
11. 11

    Pressure test the system
    Using a coolant pressure tester with the appropriate adapter, pressurize the battery cooling system to 15 PSI. Hold pressure for 10 minutes and monitor for any pressure drop. Visually inspect all connection points for signs of leakage. If pressure drops more than 2 PSI, identify and repair the leak before proceeding.
12. 12

    Verify coolant concentration
    Using a coolant refractometer, verify that the coolant concentration meets Rivian specifications for the EDV 500 battery cooling system. Proper concentration is critical for both freeze protection and corrosion inhibition. Adjust if necessary by adding premixed coolant or adjusting concentration as specified.
13. 13

    Perform system function test
    Using the diagnostic tool, command the battery cooling pump to operate at various speeds (low, medium, high). Verify smooth operation with no unusual noises. Monitor coolant flow through the sight glass if equipped. Check for proper coolant circulation by feeling temperature of coolant lines while pump operates. Verify battery cooling system temperature sensor readings are within normal range on diagnostic tool.
14. 14

    Reinstall underbody shields
    Clean all underbody shield mounting surfaces. Reinstall aerodynamic shields and underbody panels in reverse order of removal. Ensure all fasteners are properly seated and torqued. Verify that no cooling lines or wiring are pinched or stressed by shield installation.
15. 15

    Final system verification
    Lower vehicle to ground. Power up vehicle completely. Using the diagnostic tool, verify no cooling system fault codes are present. Check coolant level in reservoir once more with vehicle level and at operating temperature. Top off if necessary to MAX line. Run a final diagnostic scan to confirm all battery thermal management systems are functioning correctly. Document all work performed and reset service intervals in vehicle system if applicable.

Reassembly

1. Ensure all coolant line connections are fully seated with positive engagement clicks heard
2. Verify all electrical connectors are properly mated with locking tabs engaged
3. Double-check that all underbody shields are properly installed to prevent cooling system damage from road debris
4. Confirm coolant reservoir is filled to MAX cold fill line with vehicle at ambient temperature

Verification

• Start vehicle and verify no warning lights or messages related to battery cooling system appear on instrument cluster
• Using diagnostic tool, verify battery cooling system is operating within normal temperature range (typically 15-25°C at rest)
• Check for any visible coolant leaks around all serviced connections with vehicle running
• Verify coolant level remains stable at MAX line after initial heat cycle
• Test drive vehicle for 15-20 minutes including highway speeds and verify battery thermal management system maintains proper temperature
• Perform final diagnostic scan to confirm no fault codes are present
• Verify cooling pump activation can be heard when vehicle demands battery cooling (after extended driving or fast charging)

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