Cabin Heater - PTC

This procedure covers the removal and replacement of the PTC (Positive Temperature Coefficient) cabin heater assembly on the 2023 Rivian EDV 500 electric delivery van.

Warnings

Tools required

Parts

• PTC Cabin Heater Assembly × 1 — Use OEM Rivian specification
• Coolant hose O-rings × 4 — Use OEM Rivian specification
• HV connector seal/gasket × 1 — Use OEM Rivian specification
• Dash panel clips × 1 — As needed for replacement

Fluids

• EV Battery/Motor Coolant — 2 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Ensure vehicle has been powered off for at least 10 minutes
3. Verify 12V battery is fully charged (important for diagnostic verification)
4. Using Rivian diagnostic software, perform HV system shutdown and verification
5. Disconnect 12V battery negative terminal
6. Remove HV disconnect service plug from battery pack (located under rear cargo area)
7. Verify zero voltage at HV bus using insulated multimeter and proper testing procedure
8. Allow coolant system to cool to ambient temperature (minimum 30 minutes after last operation)
9. Place coolant drain pan under vehicle beneath front coolant drain location
10. Take photographs of all connectors and hose routing for reference during reassembly

Procedure

1. 1

   Access driver-side lower dash area
   Remove the driver-side lower dash panel by removing four T25 Torx screws. Carefully pull panel away from dash to release retaining clips. Disconnect any electrical connectors attached to the panel (if equipped with knee airbag or storage bin lighting). Set panel aside in protected area.
2. 2

   Drain cooling system
   Locate the coolant drain valve on the lower coolant line beneath the driver-side front area. Attach drain hose to valve and route into drain pan. Open drain valve and drain approximately 2 gallons of coolant. Close drain valve when flow stops. Note the coolant condition and color for reference.
3. 3

   Disconnect PTC heater coolant lines
   Locate the two coolant quick-connect fittings on the PTC heater unit visible behind the dash opening. Press the release collar on each quick-connect while pulling the line away from the heater. Have shop towels ready to catch residual coolant. Cap or plug the open coolant lines to prevent contamination.
4. 4

   Remove center console front section
   Remove the center console front trim panel to access the underside of the dash. Remove six T30 Torx screws securing the console front section. Disconnect USB and power outlet connectors. Carefully lift and remove the console front section to provide access to the PTC heater mounting area.
5. 5

   Disconnect PTC heater high voltage connector
   Wearing HV insulated gloves, locate the orange high voltage connector on the PTC heater. Press the orange safety lock tab and slide it away from the connector. Squeeze the connector release tabs on both sides while pulling the connector straight away from the heater. Verify no visible damage to connector pins. Secure the HV cable away from work area.
6. 6

   Disconnect low voltage control connector
   Locate the gray low voltage control connector on the side of the PTC heater assembly. Press the connector lock tab and pull connector straight away from heater. Inspect connector pins for damage or corrosion.
7. 7

   Remove PTC heater mounting fasteners
   Remove four 10mm hex bolts securing the PTC heater assembly to the HVAC housing and mounting bracket. Support the heater unit while removing the final bolt as the assembly is heavy. Note the location of any ground straps or brackets attached to mounting bolts.
8. 8

   Remove PTC heater assembly
   Carefully maneuver the PTC heater assembly out through the dash opening. The unit may need to be rotated and angled to clear surrounding components. Have an assistant support the unit from below if needed. Once clear, place the old heater on a protected work surface.
9. 9

   Inspect mounting area and connections
   Inspect the HVAC housing mounting surface for damage or cracks. Check all coolant connection ports for debris or damage. Inspect the high voltage connector mounting point for any signs of arcing or heat damage. Clean the mounting surface with a lint-free cloth.
10. 10

    Prepare new PTC heater for installation
    Unpack the new PTC heater assembly and verify part number matches application. Install new O-rings on both coolant ports, lightly lubricating with coolant. If supplied, install new HV connector seal. Verify all mounting tabs and brackets are intact.
11. 11

    Install new PTC heater assembly
    Carefully guide the new PTC heater into position through the dash opening, reversing the removal path. Align the mounting holes with the HVAC housing and bracket. Install all four 10mm mounting bolts finger-tight, ensuring proper alignment. Tighten mounting bolts in a cross pattern to ensure even seating of the unit.
12. 12

    Reconnect electrical connections
    Connect the gray low voltage control connector to the PTC heater until it clicks into place. Wearing HV insulated gloves, connect the orange high voltage connector to the heater, ensuring proper alignment. Push firmly until connector seats completely. Slide the orange safety lock into the locked position. Verify connection is secure by gently pulling on the cable.
13. 13

    Reconnect coolant lines
    Remove caps or plugs from coolant lines. Push each coolant quick-connect fitting onto the PTC heater ports until an audible click is heard. Pull on each line to verify it is securely locked. Verify the release collars are in the locked position.
14. 14

    Refill and vacuum fill coolant system
    Connect vacuum pump to coolant system fill port. Pull vacuum on the system to -25 inHg and hold for 5 minutes to check for leaks. If vacuum holds, draw EV coolant into the system through the vacuum. Add approximately 2 quarts or until proper level is reached in expansion tank. Burp system according to Rivian service procedures.
15. 15

    Reinstall interior components and reconnect power
    Reinstall center console front section and secure with six T30 Torx screws. Reconnect all USB and power outlet connectors. Reinstall driver-side lower dash panel and secure with four T25 Torx screws. Reconnect 12V battery negative terminal. Reinstall HV disconnect service plug in battery pack.

Reassembly

1. Ensure all panel clips are properly seated and panels are flush with surrounding surfaces
2. Verify all electrical connectors are fully seated with locking tabs engaged
3. Double-check coolant quick-connects are properly locked before operation
4. Confirm HV disconnect plug is fully inserted and locked before powering vehicle

Verification

• Using Rivian diagnostic software, clear any fault codes and perform PTC heater functional test
• Power on the vehicle and verify no HV system warnings or fault codes appear
• Enable cabin heating and verify PTC heater activates (monitor with scan tool)
• Check for proper heat output at cabin vents within 2-3 minutes of activation
• Verify coolant level in expansion tank is at proper mark when system is at operating temperature
• Inspect all coolant connections for leaks with system at operating temperature and pressure
• Verify no unusual noises from PTC heater during operation
• Test cabin heating at multiple temperature settings and fan speeds
• Perform a test drive and verify consistent cabin heating performance
• Recheck coolant level after test drive and top off if necessary

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