Heater Unit/Core Replacement
NOTE: The battery terminal disconnection/reconnection procedure must be done before and after doing these procedures because some systems store data in memory that is lost when the battery is disconnected.
SRS components are located in this area. Review the SRS component locations, LHD model, RHD model and the precautions and procedures before doing repairs or service.
  1. Do the battery terminal disconnection procedure.
  1. Make sure the ignition is LOCK (0), then disconnect the negative cable from the battery.
  1. When the engine is cool, drain the engine coolant from the radiator, R20A3 engine model, K24Z3 engine model.
  1. From under the hood, slide the hose clamps (A) back. Disconnect the inlet heater hose (B) and the outlet heater hose (C) from the heater unit. Note the orientation 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.