| 摘要 |
PROBLEM TO BE SOLVED: To simplify the structure of a vehicle electric system by judging that an abnormality has occurred in the air pressure in the tires of the steering wheel when the difference or ratio between a detected steering torque and the reference steering torque exceeds a predetermined value. SOLUTION: A CPU 31 receives detection values from a steering angle sensor 15, a vehicle speed sensor 16, and a torque sensor 13. A RAM 32 reads out a reference steering torque as a reference value to detect decrease in air pressure in tires based on those detection values. To the RAM 32, a reference steering torque corresponding to the steering angle and vehicle speed detection values is read out based on the predetermined reference steering torque data according to steering angle and vehicle speed. Then, the CPU 31 compares the read out reference steering torque with a steering torque detection value detected by the torque sensor 13, and if the detection value exceeds the reference steering torque by a predetermined ratio or predetermined value or larger, the alarm lamp on a display unit 18 of the vehicle lights up. |
