EXHAUST HEAT RECIRCULATION SYSTEM ON-VEHICLE INSPECTION

PROCEDURE


  1. INSPECT FRONT EXHAUST PIPE ASSEMBLY


    1. Inspect the exhaust flow control valve operation.


      1. Remove the exhaust pipe gas control actuator sub-assembly.

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      2. A013AOEC01
        *1 Valve Plate
        *a Insertion Direction
        *b Protective Tape

        Using a screwdriver with its tip wrapped with protective tape, move the exhaust flow control valve towards the bottom of the vehicle by pushing the valve plate in the direction shown by the arrow in the illustration. Check that the valve moves smoothly.

        OK
        Valve moves smoothly.

        If the valve is stuck or does not move smoothly, replace the front exhaust pipe assembly (TWC: Front and Rear Catalyst).

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      3. Install the exhaust pipe gas control actuator sub-assembly.

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    2. Inspect the exhaust pipe gas control actuator sub-assembly


      1. Connect the GTS to the DLC3.

      2. Turn the power switch on (IG).

      3. Turn the GTS on.

      4. Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.


        Powertrain > Engine and ECT > Data List
        Tester Display
        Coolant Temp
      5. A0139PY

        While checking the engine coolant temperature with the GTS, check the operation of the exhaust pipe gas control actuator rod when the temperature rises.

        Standard
        Condition Rod Operation
        Cold (below approximately 71°C (160°F)) → Warmed up (approximately 80°C (176°F) or higher) Rod gradually extends smoothly as the temperature rises

        If the exhaust pipe gas control actuator rod does not extend smoothly, replace the exhaust pipe gas control actuator sub-assembly.

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        Tech Tips


        • After the engine has warmed up (the thermostat temperature is approximately 80°C (176°F) or higher), the rod should be extended approximately 7.2 mm (0.283 in.) or more compared to when the engine is cold (the thermostat temperature is below approximately 71°C (160°F)).

        • The coolant temperature shown in the Data List may slightly deviate from the thermostat temperature. This is because the Data List value indicates the temperature detected by the engine coolant temperature sensor, which is mounted on the engine, while the thermostat is positioned in the exhaust pipe gas control actuator sub-assembly.

        • If it is difficult to check while the rod is operating, allow the engine to cool down until the coolant temperature matches the ambient temperature and then check the rod operation again.

      6. Check for any cracks or damage on the exhaust pipe gas control actuator rod.

        OK
        No cracks or damage is found.

        If any cracks or damage is found, replace the front exhaust pipe assembly (TWC: Front and Rear Catalyst).

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  2. INSPECT FOR ENGINE COOLANT LEAK FROM FRONT EXHAUST PIPE ASSEMBLY

    CAUTION:

    Do not remove the radiator cap while the engine and radiator are still hot. Pressurized hot engine coolant and steam may be released and cause serious burns.

    Note

    Before performing this inspection, turn the A/C switch off.


    1. Turn the power switch off. Check for engine coolant leaks from the front exhaust pipe assembly (TWC: Front and Rear Catalyst) and the heater hose around the engine coolant temperature sensor.

    2. Add engine coolant to the reserve tank and install a radiator cap tester.

    3. Pump the radiator cap tester to 118 kPa (1.2 kgf/cm2, 17 psi), and then check that the pressure does not drop.

      If the pressure drops, check the front exhaust pipe assembly (TWC: Front and Rear Catalyst) and the heater hose around the engine coolant temperature sensor for leaks.