METER / GAUGE SYSTEM, Diagnostic DTC:B1503

DTC Code DTC Name
B1503 Exhaust Heat Management Warning Detected

DESCRIPTION

This DTC is stored and displays an engine coolant temperature warning when the combination meter assembly (meter circuit plate) detects a malfunction in the engine coolant temperature sensor that is connected to the combination meter assembly (meter circuit plate) via a direct line.

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.

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

Diagnosis Condition:


  • The power switch is on (IG).

  • IG power source voltage is 9.5 V or more.

Malfunction Status:


  • Engine coolant temperature sensor circuit open or shorted

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

  • Harness or connector

  • Engine coolant temperature sensor

  • Combination meter assembly (Meter circuit plate)

  • Exhaust heat recirculation system

 DTC stored -

WIRING DIAGRAM

A003OO9E11
*a Engine Coolant Temperature Sensor
*b Combination Meter Assembly (Meter Circuit Plate)

CAUTION / NOTICE / HINT

Note

When replacing the combination meter assembly, always replace it with a new one. If a combination meter assembly which was installed to another vehicle is used, the information stored in it will not match the information from the vehicle and a DTC may be stored.

PROCEDURE


  1. READ VALUE USING GTS (COOLANT TEMPERATURE)


    1. Put the engine in inspection mode (maintenance mode).

      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. Read the Data List according to the display on the GTS.


      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 the engine is warmed.

      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 (ENGINE COOLANT TEMPERATURE SENSOR - COMBINATION METER ASSEMBLY (METER CIRCUIT PLATE))


    1. Disconnect the A10 engine coolant temperature sensor connector.

    2. Disconnect the I6 combination meter assembly (meter circuit plate) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A10-2 (TWS3) - I6-23 (TWS3) Always Below 1 Ω
      A10-1 (E2) - I6-3 (E2) Always Below 1 Ω
      A10-2 (TWS3) or I6-23 (TWS3) - Body ground Always 10 kΩ or higher
      A10-1(E2) or I6-3 (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 (METER CIRCUIT PLATE) Click here

    NG

    REPLACE ENGINE COOLANT TEMPERATURE SENSOR Click here