| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a failure determination device of a fuel temperature sensor capable of precisely executing failure determination even in such conditions that the reliability of detection result of the fuel temperature sensor.SOLUTION: A failure determination device 1 of a fuel temperature sensor 31 includes an ECU2. The ECU2 calculates the proportion of a fuel amount returned into a fuel supply path 12 from a common rail 16 via a return path 21, of fuel amount supplied into the common rail 16 as a return flow rate ratio r_PCV (step 58), calculates an estimation fuel temperature Tf_sim as an estimation value of fuel temperature at the site of the fuel temperature sensor 31 of the fuel supply path 12 by using the return flow rate ratio r_PCV (step 60), and when the estimation fuel temperature Tf_sim reaches a prescribed low temperature threshold Tlow before a detection fuel temperature Tf_sen as a fuel temperature detected by the fuel temperature sensor 31, determines that the fuel temperature sensor 31 is in failure (step 35 to 39).</p> |
