Method and apparatus for assessing the rationality of a transmission fluid temperature measure
First Claim
1. A method of assessing rationality of a measured temperature of fluid in a transmission, where the transmission is coupled to an engine, comprising the steps of:
- obtaining a temperature of the engine;
assessing that said measured temperature is rational if said measured temperature is within a calibrated value of the temperature of the engine for at least a predetermined time interval; and
assessing that said measured temperature is skewed high if said measured temperature exceeds the temperature of the engine by at least said calibrated value for at least a predetermined time interval.
1 Assignment
0 Petitions
Accused Products
Abstract
The rationality of a measured temperature of transmission fluid is assessed by comparing it to an engine coolant temperature. The rationality assessment is enabled when the ambient air temperature is reliably determined and deemed normal, a sufficient soak condition is confirmed, and the measured temperature, the engine temperature and the ambient air temperature are all within prescribed ranges. The rationality assessment monitors the ambient temperature relative to the initial engine temperature during the assessment period, and the assessment is disabled if the ambient air temperature deviates from the initial engine temperature by more than a calibrated value.
-
Citations
20 Claims
-
1. A method of assessing rationality of a measured temperature of fluid in a transmission, where the transmission is coupled to an engine, comprising the steps of:
-
obtaining a temperature of the engine; assessing that said measured temperature is rational if said measured temperature is within a calibrated value of the temperature of the engine for at least a predetermined time interval; and assessing that said measured temperature is skewed high if said measured temperature exceeds the temperature of the engine by at least said calibrated value for at least a predetermined time interval. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. Apparatus for assessing rationality of a measured temperature of fluid in a transmission, where the transmission is coupled to an engine, comprising:
-
an engine temperature sensor for sensing a temperature of the engine; and diagnostic means responsive to the measured temperature and the temperature of the engine for; assessing that said measured temperature is rational if said measured temperature is within a calibrated value of the temperature of the engine for at least a predetermined time interval; and assessing that said measured temperature is skewed high if said measured temperature exceeds the temperature of the engine by at least said calibrated value for at least a predetermined time interval. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
-
Specification