P0181 - FUEL TEMPERATURE SENSOR A CIRCUIT RANGE / PERFORMANCE

DTC P0181 OBDII code is set when the PCM (Powertrain Control Module) encounters a voltage signal on the Fuel Temperature Sensor (FTF) circuit that is not within a range determined by the manufacturer.

The Fuel Temperature Sensor (FTF) is usually part of the Fuel Composition Sensor (FCS). It gives the PCM an accurate reading of the fuel composition and temperature. It is located in the line between the fuel tank and the fuel rail.

If the PCM detects an input signal from the FCS Sensor which shows that the fuel temperature is not within the expected range or if the fuel temperature varies by a greater degree than expected at ambient temperature, this code will illuminate along with the Check Engine light.

• MIL light on.
• Other fuel composition codes are set.
• The vehicle will lose power due to fuel temperature problems.
• The ECM activates the P0181 code in memory

The reasons for setting the P0181 OBD2 fault code are:

• Perhaps the Ambient Air Temperature (AAT) Sensor is faulty.
• The Composition/Fuel Temperature Sensor may have failed.
• System-related circuits may have bad wiring or connectors.
• The PCM may have a programming error.
• Defective ECM.

The respective troubleshooting steps related to the P0181 OBDII error code are these:

• Consult the TSB (Technical Service Bulletins) that correspond to your vehicle.
• Visually inspect all harnesses and wiring harness connectors related to the system. All components that have burn spots, chafing or other problems should be repaired or replaced.
• The FTF Sensor is supplied with a 5-volt reference and a ground connection. Check with a DVOM the reference voltage and that there is good ground at the sensor connector. Also, check that the corresponding circuits at the PCM connector have the reference voltage present.
• Replace the Fuel Temperature Sensor (FTF).