METER / GAUGE SYSTEM, Diagnostic DTC:B1503

DTC Code DTC Name
B1503 Exhaust Heat Management Warning Detected

DESCRIPTION

This DTC is stored when the combination meter assembly detects a malfunction in the engine coolant temperature sensor that is connected to the combination meter assembly via a direct line.

DTC No. Detection Item DTC Detection Condition Trouble Area Memory
B1503 Exhaust Heat Management Warning Detected

When IG voltage is 9.5 V or more and the following condition is detected:


  • Engine coolant temperature sensor circuit open or shorted

  • Temperature is 120°C (248°F) or more

  • Harness or connector

  • Engine coolant temperature sensor

  • Combination meter assembly

 DTC stored

Tech Tips

This DTC is for the engine coolant temperature sensor which is used to detect the engine coolant temperature for the exhaust heat recirculation system, not for the engine coolant temperature sensor which is used for the SFI system.

WIRING DIAGRAM

A01KT6RE03
*a Engine Coolant Temperature Sensor
*b Combination Meter Assembly

PROCEDURE


  1. READ VALUE USING GTS (COOLANT TEMPERATURE)


    1. Set the vehicle in maintenance mode using the GTS.

      Click here

    2. Connect the GTS to the DLC3.

    3. Turn the power switch on (IG).

    4. Turn the GTS on.

    5. Enter the following menus: Body Electrical / Combination Meter / Data List.

    6. Check the values by referring to the table below.


      Body Electrical > Combination Meter > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Coolant Temperature Engine coolant temperature 0 to 127.5°C (0 to 261.5°F) 75 to 100 °C (167 to 212°F) (After warming up engine) -

      Body Electrical > Combination Meter > Data List
      Tester Display
      Coolant Temperature
      OK
      Engine coolant temperature displayed on the GTS is 75 to 100°C (167 to 212°F) after warming up.

      Note

      If the engine coolant temperature exceeds 100°C, the cooling system is malfunctioning. Stop the engine immediately.

      Tech Tips

      The coolant temperature value in this inspection is the data sent from the engine coolant temperature sensor for the SFI system.

      Result
      Proceed to
      OK
      NG

    NG

    GO TO EXHAUST HEAT RECIRCULATION SYSTEM Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ENGINE COOLANT TEMPERATURE SENSOR)


    1. Disconnect the E46 combination meter assembly connector.

    2. Disconnect the D2 engine coolant temperature sensor connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      E46-29 (TWS3) - D2-2 (TSW3) Always Below 1 Ω
      E46-29 (TWS3) - Body ground Always 10 kΩ or higher
      E46-30 (E2) - D2-1 (E2) Always Below 1 Ω
      E46-30 (E2) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT ENGINE COOLANT TEMPERATURE SENSOR


    1. Remove the engine coolant temperature sensor.

      Click here

    2. Inspect the engine coolant temperature sensor.

      Click here

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here

    NG

    REPLACE ENGINE COOLANT TEMPERATURE SENSOR Click here