System and method of controlling idle-stop vehicle

A system for controlling an idle-stop vehicle, comprising:

• a hydraulic source;
• a forward clutch which is engaged through the hydraulic source;
• and
• an electronic control unit (ECU) which carries out an idle stop for stopping an engine when idle-stop permission conditions are established, the ECU carrying out an engine restart and an engagement of the forward clutch when idle-stop release conditions are established after an engine stop, the ECU being so programmed as to:
• estimate a heat generation amount of the forward clutch at the engine restart after the idle stop,
• permit a next idle stop when the heat generation amount is smaller than a first set value,
• permit the next idle stop, after a lapse of a predetermined time, when the heat generation amount is equal to or greater than the first set value and equal to or smaller than a second set value which is greater than the first set value, and
• prohibit the next idle stop when the heat generation amount is greater than the second set value.