Patent ID: 7373234

Claim:
A method of controlling a solenoid in a solenoid-operated electro-hydraulic pressure control module where a solenoid output pressure defining a control pressure varies in accordance with a solenoid control current, said method comprising the steps of: providing an up-characteristic data structure including data corresponding to an up control pressure versus control current (P-I) characteristic for increasing control pressure; providing a down-characteristic data structure including data corresponding to a down control pressure versus control current (P-I) characteristic for a decreasing control pressure; determining an up/down direction parameter associated with a prevailing control pressure and a commanded control pressure; obtaining a pair of current values from the up-characteristic data structure and the down-characteristic data structure in accordance with the commanded control pressure; interpolating a required solenoid control current between the pair of current values as a function of the up/down direction parameter; and applying the required solenoid control current to the solenoid.