EXHAUST HEAT RECIRCULATION SYSTEM ON-VEHICLE INSPECTION


  1. INSPECT FRONT EXHAUST PIPE ASSEMBLY


    1. Inspect the exhaust flow control valve operation.


      1. Remove the exhaust pipe gas control actuator Click here.

      2. A003W50E01
        Text in Illustration
        *A w/ Pin Top Plate
        *B w/o Pin Top Plate
        *1 Valve Plate
        *a Insertion Direction

        Using a screwdriver, 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 Click here.

      3. Install the exhaust pipe gas control actuator Click here.

    2. Inspect the exhaust pipe gas control actuator.


      1. Connect the intelligent tester to the DLC3.

      2. Turn the power switch on (IG).

      3. Turn the tester on.

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

      5. A003X4EE01
        Text in Illustration
        *A w/ Pin Top Plate
        *B w/o Pin Top Plate

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

        Standard
        Condition Rod Operation
        Cold (below approx. 71°C (160°F)) → Warmed up (approx. 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 front exhaust pipe assembly Click here.

        Tech Tips


        • After the engine has warmed up (the thermostat temperature is approximately 80°C (176°F) or higher), the rod extends approximately 7.2 mm (0.284 in.) or more compared to when the engine is cold (the thermostat temperature is below 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.


        • 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 Click here.

  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

    Be sure to turn the A/C switch off before starting the following inspection.


    1. Turn the power switch off. Check for engine coolant leaks from the front exhaust pipe assembly 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 cap tester to 118 kPa (1.2 kgf/cm2, 17 psi), and then check that the pressure does not drop.

      If the reading drops, check for leaks from the front exhaust pipe assembly or heater hose around the engine coolant temperature sensor.