DTC P0181: Fuel Temperature Sensor Circuit Range/Performance Problem

CIRCUIT OPERATION
• 5-volt voltage is applied to the fuel temperature sensor output terminal (terminal 1) from the PCM (terminal 51) via the resistor in the PCM.
• The fuel temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases. The ground terminal (terminal 3) is grounded to the vehicle body.
TECHNICAL DESCRIPTION
• The fuel temperature sensor converts the fuel temperature to a voltage.
• The PCM detects the fuel temperature in the fuel tank with this output voltage.
DTC SET CONDITIONS

Check Conditions
The intake air temperature is -10°C (14°F) or higher when the engine is started.
Intake air temperature is higher than 30°C (86°F).
Barometric pressure is higher than 76 kPa (11psi).

Judgement Criteria
• Fuel temperature sensor output voltage has continued to be 4.6 volts or higher for 2 seconds.
or
• Fuel temperature sensor output voltage has continued to be 0.1 volt or lower for 2 seconds.
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are: )
• Fuel temperature sensor failed.
• Open or shorted fuel temperature sensor circuit, or loose connector.
• PCM failed.