Owner's Manual

MTC-22
AIR CONDITIONER CONTROL
Revision: March 2005 2005 Altima
quently, HOT/COLD, DEFROST/VENT or FRESH/RECIRCULATION operation is selected. The new selection
data is returned to the front air control.
TRANSMISSION DATA AND TRANSMISSION ORDER
Front air control data is transmitted consecutively to each of the door motors following the form shown in figure
below.
Start: Initial compulsory signal sent to each of the door motors.
Address: Data sent from the front air control is selected according to data-based decisions made by the air mix
door motor, mode door motor and intake door motor.
If the addresses are identical, the opening angle data and error check signals are received by the door motor
LCUs. The LCUs then make the appropriate error decision. If the opening angle data is normal, door control
begins.
If an error exists, the received data is rejected and corrected data received. Finally, door control is based upon
the corrected opening angle data.
Opening angle: Data that shows the indicated door opening angle of each door motor.
Error check: Procedure by which sent and received data is checked for errors. Error data is then compiled.
The error check prevents corrupted data from being used by the air mix door motor, mode door motor and
intake door motor. Error data can be related to the following problems.
● Abnormal electrical frequency
● Poor electrical connections
● Interference from other signal transmission lines
● Signal level fluctuation
Stop signal: At the end of each transmission, a stop operation, in-operation, or internal problem message is
delivered to the front air control. This completes one data transmission and control cycle.
AIR MIX DOOR CONTROL
The air mix door is controlled by the front air control based on input from the temperature dial setting.
WJIA0878E
WJIA0882E