Auto Idle Stop System Control During A/C Use: Visibility

To avoid windows fogging, the climate control unit disables the auto idle stop when it determines that the windows are likely to be fogged, based on the humidity sensor value and the drive signal input from the wiper. The calculation of the duration of the auto idle stop varies between ECON OFF Mode and ECON ON Mode. In ECON ON Mode, the climate control unit considers only visibility (prevention of window fogging). In ECON OFF Mode, the unit also considers the comfortable environment inside the vehicle. ECON ON Mode can extend the duration of the auto idle stop, which can improve fuel economy.

When the windows get fogged during auto idle stop, the engine restarts when DEF mode is turned on.

If the climate control unit detects a sensor malfunction, or if the PCM detect a problem with the communication line to the climate control unit during A/C use, auto idle stop is disabled, and the IMA indicator comes on to alert the driver of the problem. The climate control unit may disable auto idle stop under other conditions as well. For more information, refer to the IMA SYSTEM article.