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 water temperature sensor that is connected to the combination meter assembly via a direct line.

DTC No. DTC Detection Condition Trouble Area
B1503

When IG voltage is 9.5 V or more and any of the following conditions is detected:


  1. Water temperature sensor operation malfunction

  2. Water temperature sensor circuit open or short

  3. Engine coolant temperature is 120°C (248°F) or more

  • Harness or connector

  • Water temperature sensor

  • Combination meter assembly

Tech Tips

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

WIRING DIAGRAM

A003U57E01

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (COOLANT TEMPERATURE)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the intelligent tester on.

    4. Set the vehicle in the maintenance mode using the intelligent tester Click here.

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

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

      Combination Meter
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Coolant Temperature Engine coolant temperature/-40 to 127.5°C (-40 to 261.5°F) After warming up: 80 to 100°C (176 to 212°F)

      • If -60°C (-76°F): Sensor circuit open

      • If 140°C (284°F) or more: Sensor circuit shorted
      OK
      Engine coolant temperature displayed on the intelligent tester is 80 to 100°C (176 to 212°F) after warming up

    NG

    GO TO EXHAUST HEAT RECIRCULATION SYSTEM Click here

    OK

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


    1. Disconnect the D2 connector.

    2. Disconnect the E46 connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D2-2 (TWS3) - E46-7 (TWS3) Always Below 1 Ω
      D2-1 (E2) - E46-26 (E2) Always Below 1 Ω
      D2-2 (TWS3) or E46-7 (TWS3) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. WATER TEMPERATURE SENSOR


    1. A003UQ4E02
      Text in Illustration
      *1

      Component without harness connected

      (Water Temperature Sensor)
      *2 Resistance (kΩ)
      *3 Temperature (°C (°F))

      Remove the water temperature sensor Click here.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (E2) - 2 (TWS3) Temperature is 20 °C (68°F) 2.32 to 2.59 kΩ
      1 (E2) - 2 (TWS3) Temperature is 80 °C (176°F) 0.310 to 0.326 kΩ

    NG

    REPLACE WATER TEMPERATURE SENSOR Click here

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here