Heater Unit/Core Replacement

SRS components are located in this area. Review the SRS component locations (see COMPONENT LOCATION INDEX ), and the precautions and procedures (see PRECAUTIONS AND PROCEDURES ) before doing repairs or service.

1. Do the battery terminal disconnection procedure (see USING THE GR8 BATTERY DIAGNOSTIC STATION ).
2. Disconnect the front receiver line and front suction line from the front evaporator core (see FRONT EVAPORATOR CORE REPLACEMENT  ).
3. When the engine is cool, drain the engine coolant from the radiator (see COOLANT CHECK ).
4. Front under the hood, remove the clamp (A). Slide the hose clamps (B) back. Then disconnect the inlet heater hose (C) and the outlet heater hose (D) from the heater unit. Note the layout of the hose.

   Engine coolant will run out when the hoses are disconnected; drain it into a clean drip pan. Be sure not to let coolant spill on the electrical parts or the painted surfaces. If any coolant spills, rinse it off immediately.

   Fig 1: Locating Clamp, Hose Clamps, Inlet Heater Hose And Outlet Heater Hose

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
5. Remove the mounting nuts from the heater unit. Take care not to damage or bend the fuel lines or brake lines, etc.
   Fig 2: Locating Heater Unit Mounting Nuts

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
6. Remove the dashboard (see DASHBOARD REPLACEMENT ).
7. Disconnect the connector (A) from the front blower motor. Detach the wire harness clips (B).
   Fig 3: Locating Connector, Front Blower Motor And Wire Harness Clips

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
8. Disconnect the connector (A) from the headlight leveling control unit, then detach the harness clip (B).
   Fig 4: Locating Connector, Headlight Leveling Control Unit And Harness Clip

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
9. Disconnect the connectors (A) from the front mode control motor, the passenger's air mix control motor, the recirculation control motor, and the front power transistor. Detach the wire harness clips (B).
   Fig 5: Locating Front Mode Control Motor Connectors And Wire Harness Clips

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
10. Disconnect the connectors (A) from the driver's air mix control motor and the front evaporator temperature sensor. Detach the wire harness clips (B), then remove the wire harness (C).
    Fig 6: Locating Driver's Air Mix Control Motor Connector, Wire Harness Clips And Wire Harness

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
11. Turn over the carpet. Detach the wire harness clips (A) and the rear heater duct mounting clips (B), then remove the rear heater duct (C).
    Fig 7: Locating Wire Harness Clips, Rear Heater Duct Mounting Clips And Rear Heater Duct

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
12. Remove the mounting nuts. Slide the blower-heater unit (A), then remove the drain hose (B) and blower-heater unit.
    Fig 8: Locating Nuts, Blower-Heater Unit, Drain Hose And Blower-Heater Unit

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
13. Remove the self-tapping screws and the passenger's heater duct (A). Remove the self-tapping screws and the expansion valve cover (B). Remove the self-tapping screw and the front heater core cover (C). Remove the self-tapping screws, the heater pipe brackets (D), the grommets (E), and carefully pull out the front heater core (F).
    Fig 9: Locating Passenger's Heater Duct, Expansion Valve Cover, Front Heater Core Cover, Heater Pipe Brackets, Grommets And Front Heater Core

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
14. Install the front heater core, and the front evaporator core in the reverse order of removal.
15. Install the heater unit in the reverse order of removal, and note these items:
    • Do not interchange the inlet and outlet heater hoses, and install the hose clamps securely.
    • Refill the cooling system with engine coolant (see COOLANT CHECK ).
    • Make sure that there is no coolant leakage.
    • Make sure that there is no air leakage.
    • Refer to the front evaporator core replacement (see FRONT EVAPORATOR CORE REPLACEMENT  ).
16. Do the battery terminal reconnection procedure (see USING THE GR8 BATTERY DIAGNOSTIC STATION ).
17. After installation, operate the heater unit in various functions to confirm that it works properly.
18. Run the self-diagnostic function to confirm that there are no problems in the system (see HOW TO CHECK FOR DTCS WITH THE HDS  ).