AUTOMATIC AIR CONDITIONING SYSTEM : Timer A/C Control: Description

WARNING: This page is about a different car, the 2011 Nissan Leaf. However, it is still accessible from the selected car via links, so may be relevant.

When timer A/C is set on the navigation screen, the navigation system transmits the timer A/C request signal and timer A/C time setting (set vehicle occupancy time) to VCM.

Fig 1: Timer A/C Control Circuit Diagram (Automatic Air Conditioning System)
Courtesy of NISSAN MOTOR CO., U.S.A.
VCM starts 2 hours before the set timer A/C time, and sends a request to the A/C auto amp. for calculation of the A/C operating time required to achieve the target temperature, and receives the results.
When the operation time calculated by the A/C auto amp. has been reached, VCM starts the A/C auto amp. and starts pre-A/C.

Fig 2: Timer A/C Control Operation Diagram
Courtesy of NISSAN MOTOR CO., U.S.A.