What is the P0181 fault number? What is the description of Fuel Temperature Sensor “A” Circuit Range/Performance failure? How do I fix the P0181 fault code What are the symptoms and causes for the P0181 fault code
What is the P0181 Fault code? What does it all mean?
The powertrain control module (PCM), if it detects that the voltage signal is coming from either the fuel temperature sensor circuit or the fuel composition sensor circuit, “A” If the manufacturer’s programed range is exceeded, a P0181 code will be activated. The “A” The description of circuit refers to a circuit, not a specific component.
Most vehicle applications have the fuel temperature sensor as well as the fuel composition sensor integrated into a single housing. These sensors are used to give the PCM information about the fuel’s composition and temperature. It gathers information about the fuel’s ethanol, water, and other contaminants, and then calculates the fuel temperature and sends it to the PCM via an electrical signal.
Temperature is the most important factor that affects the fuel’s density. The fuel is denser the colder it is. The powertrain control module, or PCM, monitors the fuel density to determine how much fuel is injected into cylinders. It also controls the fuel temperature. The PCM uses fuel temperature sensor values to optimize engine performance and efficiently burn fuel. The sensor’s voltage signal is high when fuel is cold. It decreases as fuel heats up.
If the PCM detects that the voltage signal from the fuel temperature/composition sensor is not within the programmed range, it will assume a fault in the sensor or circuit and set a P0181 code. This means that the PCM’s self tests have shown that the sensor voltage signal is exceeding or below the set limits.
P0181 fault codes can be found on vehicles made by Mitsubishi, Ford and other manufacturers, such as Honda, Mazda, Mazda, Chevrolet or Duramax.
What causes the P0181 Fault code?
These are the most common reasons that P0181 fault codes are triggered:
- – Broken, damaged, fused or broken wires, or loose or corroded connections, as well as open or short circuit issues to sensor circuit A
- Excessive chemicals in fuel can lead to erroneous sensor readings. This can cause fuel to boil at lower temperatures, causing the sensor to fail.
- Vehicles that freeze due to inclement weather, or contain water in their tanks will not start.
- – Defective fuel temperature sensor
- – The PCM has a problem or must be reprogrammed (very unlikely).
What are the symptoms of P0181 Malfunction Code?
You may experience the following symptoms if your vehicle has a code of P0181:
- – Illumination for the check engine light
- If the fuel has been overheated or frozen, it will cause the vehicle to not start.
- – Engine misfires
- – Engine stalling
- – Hesitation / stumbling during acceleration
- – Increased fuel consumption
How to Fix the P0181 Fault Code
The fuel temperature sensor measures the fuel temperature inside the fuel tank, fuel rail or fuel pipe of gasoline engines with heaters and diesel engines. Follow the manufacturer’s recommendations for testing your vehicle and the fuel type you use.
The following repairs may be able to resolve the P0181 fault code:
- – Repair of damaged, fused, or broken wires, or loose or rusty connections, or open or short circuit problems to sensor “A”.
- – Test the fuel temperature sensor, and replace it if it is not in specification
- – Replacing a bad fuel composition sensor (in some cars both sensors are integrated).
- – Check your fuel tank, and fill it if needed. In extremely cold temperatures, check for frostbite.
- – Reprogramming and replacing the PCM (rarely).
How Serious Is the P0181 Fault Coding?
If the fuel contains too much water, or the ambient temperature is below freezing and the temperature sensor is malfunctioning, the vehicle will not turn on. The engine can stall if it exceeds the normal operating temperature or the temperature sensor circuit malfunction causes the fuel rail to become too hot. This malfunction should be fixed as soon as possible.
