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. Make sure you have the anti-theft codes for the audio system and the navigation system (if equipped).
2. Make sure the ignition is in LOCK (0), then disconnect the negative cable from the battery.
3. Disconnect the suction and receiver lines from the evaporator core (see EVAPORATOR CORE REPLACEMENT  ).
4. From under the hood, open the cable clamp (A), then disconnect the heater valve cable (B) from the heater valve arm (C). Turn the heater valve arm to the fully opened position as shown.
   Fig 1: Identifying Cable Clamp, Heater Valve Cable And Heater Valve Arm

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
5. When the engine is cool, drain the engine coolant from the radiator (see COOLANT CHECK ).
6. Slide the hose clamps (A) back, then disconnect the inlet heater hose (B) and the outlet heater hose (C) from the heater unit. 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 2: Hose Clamps, Inlet Heater Hose And Outlet Heater Hose With Torque Specifications

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
7. Remove the mounting nut from the heater unit. Take care not to damage or bend the fuel lines and the brake lines, etc.
   Fig 3: Heater Unit Mounting Nut With Torque Specifications

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
8. Remove the dashboard (see PASSENGER'S ).
9. Disconnect the connectors (A) from the driver's mode control motor, the driver's air mix control motor, the evaporator temperature sensor, the power transistor, the passenger's mode control motor, passenger's air mix control motor, and the recirculation control motor, then remove the wire harness clips (B), the wire harness (C), and the carpet clip (D).
   Fig 4: Identifying Connectors, Wire Harness Clips, Wire Harness, And Carpet Clip

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
10. Remove the heater ducts (A), then remove the mounting nuts and the blower-heater unit (B).
    Fig 5: Heater Ducts And Blower-Heater Unit With Torque Specifications

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
11. Remove the self-tapping screws, the evaporator temperature sensor (A) and the joint duct (B). Remove the self-tapping screws, then remove the passenger's heater outlet (C), and the heater core cover (D). Remove the self-tapping screws and the passenger's air mix control motor (E). Remove the self-tapping screws, the heater pipe brackets (F), the grommets (G) and carefully pull out the heater core (H) so you don't bend the inlet and outlet pipes.
    Fig 6: Identifying Evaporator Temperature Sensor, Joint Duct, Passenger's Heater Outlet, Heater Core Cover And Heater Pipe Brackets

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
12. Install the heater core and the evaporator core in the reverse order of removal.
13. 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 ).
    • Adjust the heater valve cable (see HEATER VALVE CABLE ADJUSTMENT  ).
    • Make sure that there is no coolant leakage.
    • Make sure that there is no air leakage.
    • Refer to step 8 on EVAPORATOR CORE REPLACEMENT  .
    • Enter the anti-theft codes for the audio system and the navigation system (if equipped).
    • Set the clock (on vehicles without navigation).