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DTC    B1503    Exhaust Heat Management Warning Detected

for Preparation Click here


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.
DTC Detection Condition
Trouble Area
B1503
When IG voltage is 9.5 V or more and the following condition is detected:
  1. Engine coolant temperature sensor operation malfunction
  2. Engine coolant temperature sensor circuit open or short
  3. Engine coolant temperature is 120°C (248°F) or more
  1. Harness or connector
  2. Engine coolant temperature sensor
  3. Combination meter assembly

HINT:
This DTC is for the engine coolant temperature sensor which is used to detect the engine 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


E188188E09


INSPECTION PROCEDURE

1.READ VALUE USING INTELLIGENT TESTER

  1. Set the vehicle in the maintenance mode using the intelligent tester (Click here).

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Turn the intelligent tester on.

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

  1. 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: 75 to 100°C (167 to 212°F)
    1. If -40°C (-40°F): Sensor circuit open
    2. If 140°C (284°F) or more: Sensor circuit shorted

    OK:
    Engine coolant temperature displayed on the intelligent tester is 75 to 100°C (167 to 212°F) after warming up



NG
GO TO EXHAUST HEAT RECIRCULATION SYSTEM (Click here)
OK


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

  1. Disconnect the F2 connector.

  1. Disconnect the H19 connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    F2-2 (TWS3) - H19-26 (TWS3)
    		Always
    		Below 1 Ω
    F2-1 (E2) - H19-34 (E2)
    		Always
    		Below 1 Ω
    F2-2 (TWS3) or H19-26 (TWS3) - Body ground
    		Always
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.INSPECT ENGINE COOLANT TEMPERATURE SENSOR


    E188251E05

  1. Remove the engine coolant temperature sensor (Click here).

  1. 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

    Text in Illustration 
    *a
    		Component without harness connected
    (Engine Coolant Temperature Sensor)
    *b
    		Resistance kΩ
    *c
    		Temperature °C (°F)



NG
REPLACE ENGINE COOLANT TEMPERATURE SENSOR (Click here)
OK

REPLACE COMBINATION METER ASSEMBLY (Click here)