Bosch-Common Rail System – Fuel temperature sensor
The fuel temperature sensor is located in the fuel return system in a T-piece above the fuel rail. It measures the fuel temperature in the low-pressure system.
With the help of this signal, the fuel temperature is continuously monitored to prevent overheating of the injection system. The critical fuel temperature is approx. 90 °C. When the maximum fuel temperature is approached, the fuel pressure and injected quantity is limited accordingly.
Effects of faults
In the event of a fault, the PCM assumes a maximum temperature value, which results in a reduction of the engine power output.
The monitoring system continuously checks if the signal is within the limits as well as for short circuit and open circuit. Faults on the fuel temperature sensor have no effect on the exhaust gas emissions and therefore do not affect the EOBD limits. For this reason, it is a non MIL active component.
Possible diagnostic trouble codes: P0180, P0182, P0183.