P0168 Fault code – Fuel temperature too high

What is the P0168 fault number? What’s the reason for the Fuel Temperature Too High fault code? How can I fix the P0168 fault code What are the causes and symptoms for the P0168 fault code

What is the P0168 Fault code? What does it all mean?

If the powertrain control module, (PCM), receives a voltage signal via the fuel composition sensor that indicates that the fuel temperature has reached too high, a code P0168 will be set.

The fuel temperature sensor can be integrated into the fuel composition sensors. It is an electronic component similar to a fuel filter that provides information to the PCM about the nature and temperature the fuel.

The fuel composition sensor’s job is to electronically measure the fuel’s temperature and grade. Because of the variety in fuels today, this is an important requirement. This is because the fuel’s composition determines its calorific (heat or energy) value. The PCM must know how much fuel a given volume contains in order to calculate its fuel delivery strategy. A fuel composition sensor is also used to measure the fuel’s level of water and other contaminants. These pollutants can have a major impact on the temperature of fuel delivered to injectors.

The fuel composition sensor sends square patterns of voltage waves to the PCM that indicate the fuel temperature. The level of fuel pollution affects how the wave patterns change. The fuel’s temperature and degree of pollution will affect how square and wide the patterns. The frequency of these waveforms typically ranges between one and five milliseconds. A code P0168 is set if the PCM receives a voltage signal from the fuel temperature/composition sensor indicating that the fuel temperature is too high.

Below is an image that will give you an idea about the waveforms of hot and cold fuel. The image shows that there are wide gaps between successive waves in upper row, which indicate fuel that is cold. While narrower gaps in lower row (higher frequency), indicate fuel that is hot.

P0168 fault codes can be found on many vehicles, including but not limited to Dodge, Ram and Ford models.

What is the P0168 Fault Code?

Here are some reasons why P0168 should be set.

– Defective fuel composition / temperature sensor
– Corroded, damaged, shorted or disconnected wiring and/or connectors
– Extremely contaminated or poor quality fuel
– The PCM is defective or must be reprogrammed. This happens very rarely

What are the symptoms of P0168 Trouble code?

You may experience the following symptoms if your vehicle has a P0168 code:

– Illumination and control of the check engine light
– Higher fuel consumption
– Lower engine performance
Engine stalling
– Engine running hard, or not at all
– Setting other codes for fuel system

How do I fix the P0168 fault code?

Setting this code can often be associated with poor fuel quality. If this code appears after you refuel, change the fuel or buy high-quality fuel.

There are several repairs that can resolve the P0168 fault code.

– Replacing the damaged fuel component / temperature sensor
Repair of frayed, shorted or damaged cables and connectors
– Reprogramming, testing or replacing the PCM
– Checking and changing other sensors (ambient temperature sensor, intake temperature (IAT), sensor etc. Components