ECD SYSTEM, Diagnostic DTC:P0168, P0180, P0182, P0183

DTC Code	DTC Name
P0168	Fuel Temperature Too High
P0180	Fuel Temperature Sensor "A" Circuit
P0182	Fuel Temperature Sensor "A" Circuit Low Input
P0183	Fuel Temperature Sensor "A" Circuit High Input

DESCRIPTION

The fuel temperature sensor senses the fuel temperature. A thermistor built into the sensor changes its resistance value according to the fuel temperature. The lower the fuel temperature is, the greater the thermistor resistance becomes, and the higher the fuel temperature is, the lower the thermistor resistance becomes (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. The resistor R and the fuel temperature sensor are connected in series. When the resistance value of the fuel temperature sensor changes in accordance with the fuel temperature, the voltage at terminal THF also changes. Based on this signal, the ECM corrects the pressure control compensation of the supply pump and an error.

DTC No.	DTC Detection Condition	Trouble Area
P0168	After engine is warmed up, conditions (a), (b) and (c) continue for more than 1 second: (a) Engine speed: 1000 rpm or more (b) Vehicle speed: 10 km/h (6 mph) or more (c) Fuel temperature: 96°C (205°F) or more	Open or short in fuel temperature sensor circuit Fuel temperature sensor ECM
P0180	Open or short in fuel temperature sensor circuit for 0.5 seconds	Open or short in fuel temperature sensor circuit Fuel temperature sensor ECM
P0182	Short in fuel temperature sensor circuit for 0.5 seconds	Open or short in fuel temperature sensor circuit Fuel temperature sensor ECM
P0183	Open in fuel temperature sensor circuit for 0.5 seconds	Open or short in fuel temperature sensor circuit Fuel temperature sensor ECM

Tech Tips

When DTC P0180, P0182 or P0183 is detected, check the fuel temperature by selecting the folowing menus on the intelligent tester: Powertrain / Engine and ECT / Data List / Fuel Temperature.

Temperature Displayed	Malfunction
-40°C (-40°F)	Open circuit
140°C (284°F) or more	Short circuit

WIRING DIAGRAM

INSPECTION PROCEDURE

Tech Tips

If DTCs that are related to different systems are output simultaneously while terminal E2 is used as a ground terminal, terminal E2 may have an open circuit.
Read 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.

PROCEDURE

READ VALUE USING INTELLIGENT TESTER (FUEL TEMPERATURE)

Connect the intelligent tester to the DLC3.
Turn the ignition switch to the ON position.
Turn the tester on.
Enter the following menu items: Powertrain / Engine and ECT / Data List / Fuel Temperature.

Read the value.

Standard
Same value as the actual fuel temperature.

Result

Temperature Displayed	Proceed to
-40°C (-40°F)	A
140°C (284°F) or more	B
OK (same as actual fuel temperature)	C

Tech Tips

If there is an open circuit, the intelligent tester indicates -40°C (-40°F).
If there is a short circuit, the intelligent tester indicates 140°C (284°F) or more.

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

CHECK FOR INTERMITTENT PROBLEMS

READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS)
1. Disconnect the fuel temperature sensor connector.
2. Connect terminals 1 and 2 of the wire harness side connector.
3. Connect the intelligent tester to the DLC3.
4. Turn the ignition switch to the ON position.
5. Turn the tester on.
6. Enter the following menu items: Powertrain / Engine and ECT / Data List / Fuel Temperature.
7. Read the value.
  
  Standard
  
  140°C (284°F) or more
8. Reconnect the fuel temperature sensor connector.
NG
READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN ECM) Click here

OK

REPLACE COMMON RAIL ASSEMBLY (FUEL TEMPERATURE SENSOR)
READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN ECM)
1. Disconnect the fuel temperature sensor connector.
2. Connect terminals THF and E2 of the ECM connector.
  
  Tech Tips
  
  Before checking, do a visual and contact pressure check for the ECM connector.
3. Connect the intelligent tester to the DLC3.
4. Turn the ignition switch to the ON position.
5. Turn the tester on.
6. Enter the following menu items: Powertrain / Engine and ECT / Data List / Fuel Temperature.
7. Read the value.
  
  Standard
  
  140°C (284°F) or more
8. Reconnect the fuel temperature sensor connector.
NG
REPLACE ECM

OK

REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - FUEL TEMPERATURE SENSOR)
READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS)
1. Disconnect the fuel temperature sensor connector.
2. Connect the intelligent tester to the DLC3.
3. Turn the ignition switch to the ON position.
4. Turn the tester on.
5. Enter the following menu items: Powertrain / Engine and ECT / Data List / Fuel Temperature.
6. Read the value.
  
  Standard
  
  -40°C (-40°F)
7. Reconnect the fuel temperature sensor connector.
NG
READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN ECM) Click here

OK

REPLACE COMMON RAIL ASSEMBLY (FUEL TEMPERATURE SENSOR)
READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN ECM)
1. Disconnect the ECM connector.
2. Connect the intelligent tester to the DLC3.
3. Turn the ignition switch to the ON position.
4. Turn the tester on.
5. Enter the following menu items: Powertrain / Engine and ECT / Data List / Fuel Temperature.
6. Read the value.
  
  Standard
  
  -40°C (-40°F)
7. Reconnect the ECM connector.
NG
REPLACE ECM

OK

REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - FUEL TEMPERATURE SENSOR)