How to read&repair Mercedes error P0180: Fuel temperature sensor, excessive voltage

Here are all tips for Mercedes-benz w176 Class A with fault P0180 “Fuel temperature sensor, excessive voltage”.


What’s the model?

Mercedes w176 Class A
How to scan the w170?

Via the machine MB star sd connect c4 and TCS CDP+.


What about the diagnosis result?

P018017 reading with the machine MB star sd connect c4.
with DELPHI appears P0180: Fuel temperature sensor, excessive voltage.

It may be connection problems



Tip on error P0180:

What the P0180 code means?

P0180 is a generic OBD-II code that is triggered by a malfunctioning fuel temperature sensor ‘A.’ This could indicate that the sensor is not within specification, or that the fuel temperature or fuel rail is too hot or too cold.


What causes the P0180 code?

The engine control module (ECM) sets the P0180 code to memory when it detects a malfunctioning sensor circuit; the sensor input is either below or above the specified range designed for the sensor


The fuel could be too hot or too cold?

The fuel tank or fuel rail temperature sensor could be out of sensor range, or the connector could be corroded


In diesel engines, the ECM monitors the temperature of the diesel fuel when the fuel heater is activated, and will set the P0180 code if the temperature is out of range


What are the symptoms of the P0180 code?

The vehicle will not start if the fuel is frozen from extreme cold, or if there is water in the fuel


The vehicle will not start, or may lose power and stall, if the fuel gets too hot and boils off


Excessive additives in the fuel can cause erratic sensor readings and cause the fuel to boil off at lower temperatures, causing the sensor to malfunction


How does a mechanic diagnose the P0180 code for Mercedes?

Scans codes and documents the freeze frame data, then clears the codes to verify code returns


Does a visual check of all the wiring and connections to the sensor, checking for breaks in the wiring or loose connections


Disconnects the connection to the sensor and checks to see if the sensor is testing within specifications


Takes a fuel sample to compare the actual temperature of fuel to the sensor input


Tests the diesel fuel heater for proper operation to make sure it is working to heat the fuel, without overheating the fuel


Common mistakes when diagnosing the P0180 code


Follow these simple guidelines to prevent misdiagnosis:


Do a visual check of the connections to the sensor to make sure they are making good contact with the fuel heater and fuel temperature sensor


Check the fuel for excessive additives that can cause sensors to malfunction


How serious is the P0180 code?

The vehicle will not start if excessive water is in the fuel, the ambient temperature is below freezing, and the fuel heater is defective due to the temperature sensor


The engine may misfire, hesitate, and stall if the fuel temperature exceeds normal operating temperatures due to temperature sensor circuit malfunction, or if the fuel rail gets too hot.


What repairs can fix the P0180 code?

Testing the fuel temperature sensor and replacing it if it is out of specifications

Repairing or replacing a defective connector or wiring to the sensor

Replacing the diesel fuel heater assembly with the temperature sensor

Additional comments for consideration regarding the P0180 code


The code P0180 is used on diesel engines with fuel heaters and on gasoline engines to monitor the fuel temperature in the fuel tank or at the fuel rail. Follow the manufacturer’s recommended testing procedures for the vehicle and type of fuel you are working on.