P0183 - FUEL TEMPERATURE SENSOR A CIRCUIT HIGH INPUT

The establishment of the diagnostic code P0183 indicates that the Power Train Control Module (PCM) has observed a voltage signal belonging to the Fuel Temperature Sensor (FTS), higher than expected. In general, this sensor is integrated in the Fuel Composition Sensor (FCS).

The FCS sensor sends information to the PCM, which contains the precise composition of the fuel, as well as an analysis indicating the fuel temperature. When fuel enters through the FCS sensor, check the level of contaminants present. The PCM interprets the fuel temperature as pulse width. The thicker the pulse width signal, the higher the fuel temperature level.

If the fuel temperature is above the ambient temperature, the DTC code P0183 OBD2 is saved.

• Illumination of MIL light.
• The engine may not start.
• Engine malfunction.

The establishment of DTC code P0183 OBDII indicates that one or more of the following problems has occurred:

• Short circuit due to defective FTS sensor cables or connectors.
• The Fuel Temperature Sensor (FTS) could be defective due to the presence of water or corrosion.
• Fuel Composition Sensor in poor condition.

The steps to follow to correct the fault code P0183 OBD2 are the following:

• The first thing is to consult the Technical Service Bulletins.
• Inspect the wiring and their connectors may be burned or have corrosion. If you find characteristics like that, repair or replace.
• With a digital multimeter, check the reference voltage, as well as the ground connection in the respective connector of the Fuel Temperature Sensor (FTS). If there is no reference voltage, with the multimeter, test the parallel circuits in the PCM connector. If there is no voltage in the PCM connector, it may be due to poor programming of the PCM.

• If the reference voltage is in addition to a good ground, you can observe the live data in wave form with an oscilloscope. To do this, connect the test leads to the ground circuit and the signal circuit. Observe the patterns in wave form, through the display screen. Then, use an infrared thermometer with which you will get a real temperature of the fuel, compare it with the temperature reflected in the oscilloscope. If both readings do not match, the fuel temperature sensor may be defective, replace it.