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 ) in the SRS article before doing repairs or service.

1. Make sure you have the anti-theft codes for the audio system and the navigation system (if equipped), then write down the audio presets.
2. Disconnect the negative cable from the battery.
3. Disconnect the suction and receiver lines from the evaporator core (see BLOWER UNIT COMPONENT 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; '04-05 models (see '04-05 MODELS ), '06-08 models (see '06-08 MODELS ).
6. Slide the hose clamps (A) back. Remove the bolt and water valve bracket, 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: Identifying Hose Clamps, Inlet Heater Hose And Outlet Heater Hose

   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 W/Torque Specification

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
8. Remove the dashboard (see DASHBOARD/STEERING HANGER BEAM REMOVAL/INSTALLATION ).
9. Remove the footrest and the footrest bracket.
10. Disconnect the connectors (A) from the driver's air mix control motor, the evaporator temperature sensor, the power transistor, the mode control motor, passenger's air mix control motor, and the recirculation control motor, then remove the wire harness clips (B), the connector clips (C) and the wire harness (D). Remove the heater ducts (E), then remove the mounting nuts and the blower-heater unit (F).
    Fig 4: Blower Heater Motor Connectors, Connector Clips W/Torque Specification

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
11. Remove the self-tapping screws and the joint duct A, then remove the self-tapping screws 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, the heater pipe bracket (E), the grommets (F) and carefully pull out the heater core (G) so you don't bend the inlet and outlet pipes.
    Fig 5: Identifying Self-Tapping Screw, Heater Core Cover And Passenger's Heater Outlet

    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; '04-05 models (see step 7 on '04-05 MODELS ), '06-08 models (see step 7 on '06-08 MODELS ).
    • 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 BLOWER UNIT COMPONENT REPLACEMENT  .
    • Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).
    • Enter the anti-theft codes for the audio system and the navigation system (if equipped), then enter the audio presets.