Dtc 39 (5) Fuel Temperature Sensor Circuit Malfunction


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

When using intelligent tester:

READ VALUE USING INTELLIGENT TESTER (FUEL TEMPERATURE)

READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS)

READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN ECM)

READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS)

READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN ECM)

When not using intelligent tester:

CHECK ECM (THF VOLTAGE)

INSPECT FUEL TEMPERATURE SENSOR

CHECK HARNESS AND CONNECTOR (ECM - FUEL TEMPERATURE SENSOR)

DTC 39 (5) Fuel Temperature Sensor Circuit Malfunction


DESCRIPTION

The fuel temperature sensor senses the fuel temperature. A thermistor built into the sensor changes the resistance value according to the fuel temperature. The lower the fuel temperature, the greater the thermistor resistance value, and the higher the fuel temperature, the lower the thermistor resistance value (see Fig. 1).
The fuel temperature sensor is connected to the ECM. The 5 V power source voltage in the ECM is applied to the fuel temperature sensor from terminal THF via resistor R. That is, resistor R and the fuel temperature sensor are connected in series. When the resistance value of the fuel temperature sensor changes in accordance with changes in the fuel temperature, the potential at the terminal THF also changes. Based on this signal, the ECM increases the fuel injection volume to improve driveability during low engine revolution and high fuel temperature.
Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.5L-E Engine Control System.Ecd System. Dtc 39 (5) Fuel Temperature Sensor Circuit Malfunction

DTC No.
DTC Detection Condition
Trouble Area
39 (5)
Open or short in fuel temperature sensor circuit for 0.5 sec. or more
  1. Open or short in fuel temperature sensor circuit
  2. Fuel temperature sensor
  3. ECM

WIRING DIAGRAM


Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.5L-E Engine Control System.Ecd System. Dtc 39 (5) Fuel Temperature Sensor Circuit Malfunction


INSPECTION PROCEDURE

HINT:
  1. If DTCs that are related to different systems are output simultaneously while terminal E2 is used as a ground terminal, terminal E2 may be open.
  2. Reed freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

When using intelligent tester:

1.READ VALUE USING INTELLIGENT TESTER (FUEL TEMPERATURE)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch ON.

  1. Enter the following menus: Powertrain / Engine and ECT / Data List / Fuel Temp.

    Result:
    Display
    		Proceed to
    -40°C (-40°F)
    		A
    140°C (284°F) or more
    		B
    The same as actual fuel temperature
    		C
    HINT:
    When DTC 39 (5) is present, the type of malfunction can be determined based on the fuel temperature (see below).
    Result:
    Temperature Displayed
    		Malfunction
    -40°C (-40°F)
    		Open circuit
    140°C (284°F) or more
    		Short circuit


B
Go to step 4

C
CHECK FOR INTERMITTENT PROBLEMS
A


2.READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS)


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.5L-E Engine Control System.Ecd System. Dtc 39 (5) Fuel Temperature Sensor Circuit Malfunction

  1. Disconnect the F10 fuel temperature sensor connector.

  1. Connect the sensor terminals 1 and 2 of the fuel temperature sensor harness side connector.

  1. Turn the ignition switch ON.

  1. Read the temperature value on the intelligent tester.

    Temperature:
    140°C (284°F) or more


OK
REPLACE FUEL TEMPERATURE SENSOR
NG


3.READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN ECM)


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.5L-E Engine Control System.Ecd System. Dtc 39 (5) Fuel Temperature Sensor Circuit Malfunction

  1. Connect terminals THF and E2 of the ECM connector.

  1. Turn the ignition switch ON.

  1. Read the temperature value on the intelligent tester.

    Temperature:
    140°C (284°F) or more


NG
REPLACE ECM
OK

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS)


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.5L-E Engine Control System.Ecd System. Dtc 39 (5) Fuel Temperature Sensor Circuit Malfunction

  1. Disconnect the F10 fuel temperature sensor connector.

  1. Turn the ignition switch ON.

  1. Read the temperature value on the intelligent tester.

    Temperature:
    -40°C (-40°F)


OK
REPLACE FUEL TEMPERATURE SENSOR
NG


5.READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN ECM)

  1. Disconnect the E22 ECM connector.

  1. Turn the ignition switch ON.

  1. Read the temperature value on the intelligent tester.

    Temperature:
    -40°C (-40°F)


NG
REPLACE ECM
OK

REPAIR OR REPLACE HARNESS OR CONNECTOR


When not using intelligent tester:

1.CHECK ECM (THF VOLTAGE)


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.5L-E Engine Control System.Ecd System. Dtc 39 (5) Fuel Temperature Sensor Circuit Malfunction

  1. Turn the ignition switch ON.

  1. Measure the voltage of the ECM connector.

    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    E21-5 (THF) - E21-9 (E2)
    		20°C (68°F)
    		0.2 to 3.8 V
    E21-5 (THF) - E21-9 (E2)
    		80°C (176°F)
    		0.1 to 1.5 V


OK
CHECK FOR INTERMITTENT PROBLEMS
NG


2.INSPECT FUEL TEMPERATURE SENSOR


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.5L-E Engine Control System.Ecd System. Dtc 39 (5) Fuel Temperature Sensor Circuit Malfunction

  1. Measure the resistance of the fuel temperature sensor.

    OK:
    The resistance value is within the acceptable range shown in the illustration.
    NOTICE:
    When checking the fuel temperature sensor in water, do not allow water to enter the terminals. After checking, wipe the sensor dry.


NG
REPLACE FUEL TEMPERATURE SENSOR
OK


3.CHECK HARNESS AND CONNECTOR (ECM - FUEL TEMPERATURE SENSOR)


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.5L-E Engine Control System.Ecd System. Dtc 39 (5) Fuel Temperature Sensor Circuit Malfunction

  1. Disconnect the F10 fuel temperature sensor connector.

  1. Disconnect the E21 ECM connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Specified Condition
    F10-2 - E21-5 (THF)
    		Below 1 Ω
    F10-1 - E21-9 (E2)
    		Below 1 Ω
    E21-5 (THF) - E21-9 (E2)
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ECM