DIAGNOSIS DEVICE FOR TEMPERATURE SENSOR

• US 20140341249A1
• Filed: 05/06/2014
• Published: 11/20/2014
• Est. Priority Date: 05/16/2013
• Status: Active Grant

• Current Assignee: Subaru Corp.
• Original Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Inventors: KINOSHITA, Takahiro
• Granted Patent: US 9,546,971 B2
• Time in Patent Office: Days
• US Class Current: 374/4
• CPC Class Codes: F16H 2061/1208 with diagnostic check cycles; Monitoring of failures
• CPC Class Codes: F16H 2061/1284 the failing part is a sensor
• CPC Class Codes: F16H 59/72 dependent on oil characteristics, e.g. temperature, viscosity
• CPC Class Codes: G01K 13/026 of moving liquids
• CPC Class Codes: G01K 15/007 Testing
• CPC Class Codes: G01K 2205/00 Application of thermometers in motors, e.g. of a vehicle
• CPC Class Codes: G01K 7/22 the element being a non-linear resistance, e.g. thermistor G01K7/26 takes precedence
• CPC Class Codes: G01N 25/72 Investigating presence of flaws

Abstract

A diagnosis device for a temperature sensor provided to a power transmission device transmits driving force generated by a driving power source of a vehicle. The diagnosis device includes: an output voltage estimating unit to calculate an output voltage estimation value of the temperature sensor, based on the operating state of the vehicle; and an output voltage stuck malfunction determining unit to determine an output voltage stuck malfunction of the temperature sensor, in a case where the amount of change of the output voltage estimation value is equal to or above a first threshold value, and the amount of change of output voltage of the temperature sensor is equal to or below a second threshold value.

Claims

1. A diagnosis device for a temperature sensor provided to a power transmission device that transmits driving force generated by a driving power source of a vehicle, the diagnosis device comprising:

an output voltage estimating unit to calculate an output voltage estimation value of the temperature sensor, based on the operating state of the vehicle; and

an output voltage stuck malfunction determining unit to determine an output voltage stuck malfunction of the temperature sensor, in a case where the amount of change of the output voltage estimation value is equal to or above a first threshold value, and the amount of change of output voltage of the temperature sensor is equal to or below a second threshold value.

2. The diagnosis device for a temperature sensor according to claim 1,

wherein the output voltage stuck malfunction determining unit determines the output voltage stuck malfunction, in a case where the amount of change of the output voltage estimation value is equal to or above a first threshold value and the amount of change of output voltage of the temperature sensor is equal to or below a second threshold value, and this state continues for a predetermined amount of time or longer.

3. The diagnosis device for a temperature sensor according to claim 1,

wherein the output voltage estimating unit calculates an output voltage estimation value for each of a hot external air state and a cold external air state;

and wherein the output voltage stuck malfunction determining unit determines the output voltage stuck malfunction only in a case where the output voltage estimation value is equal to or above the first threshold value in both the hot external air state and a cold external air state.

4. The diagnosis device for a temperature sensor according to claim 2,

wherein the output voltage estimating unit calculates an output voltage estimation value for each of a hot external air state and a cold external air state;

and wherein the output voltage stuck malfunction determining unit determines the output voltage stuck malfunction only in a case where the output voltage estimation value is equal to or above the first threshold value in both the hot external air state and a cold external air state.