DTC P0168 2AD-FHV

DTC P0168 Fuel Temperature Too High

 

Description

The fuel temperature sensor monitors the fuel temperature. The fuel temperature sensor has a thermistor that varies its resistance depending on the fuel temperature. When the fuel temperature is low, the resistance of the thermistor is high. When the temperature is high, the resistance is low. The variations of resistance are communicated to the ECM as changes of voltage (see Fig. 1).
The fuel temperature sensor is connected to the ECM (see below). 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 fuel temperature sensor are connected in series. When the resistance value of the fuel temperature sensor changes due to a change of 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 determines errors.
Description DTC P0168
Toyota fault code list DTC P0168 2AD-FHV

DTC No. DTC Detection Condition Trouble Area
P0168 If fuel temperature is between 35°C ( 95°F) and 60°C (140°F) at engine start, and conditions (a) and (b) are met:
(2 trip detection logic)
(a) Vehicle is driven at varying speeds (accelerating and decelerating)
(b) Fuel temperature remains within 3°C (5.4°F) of engine starting temperature		 Fuel temperature sensor
P0168 If fuel temperature is more than 60°C (140°F) at engine start, and conditions (a) and (b) are met:
(6 trip detection logic)
(a) Vehicle is driven at varying speeds (accelerating and decelerating)
(b) Fuel temperature remains within 1°C (1.8°F) of engine starting temperature, and this is continuously recorded 6 times		 Fuel temperature sensor

Inspection procedure

 

HINT:

If DTCs P0180, P0182, or P0183 is set at the same time as P0168, the fuel temperature sensor may have an open or a short circuit. Troubleshoot those DTCs first.

1.CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P0168)

  1. Connect the intelligent tester to the DLC3.

  2. Turn the ignition switch on (IG) and turn the tester ON.

  3. Enter the following menus: Powertrain / Engine and ECT / DTC.

  4. Read the DTCs.

     

    Result:
    Display (DTC Output) Proceed to
    P0168 A
    P0168 and other DTCs B

    HINT:

    If DTCs other than P0168 are output, perform troubleshooting for those codes first.

 

  B  
GO TO DTC CHART
 
A  
   
REPLACE FUEL TEMPERATURE SENSOR 

 

2AD-FHV