Owner's Manual

MTC-48
TROUBLE DIAGNOSIS
Revision: March 2005 2005 Altima
SYSTEM DESCRIPTION
Component Parts
Mode door control system components are:
● Front air control
● Mode door motor (LCU)
System Operation
The front air control receives signals from its various dials and switches. The front air control then sends air
mix door, mode door and intake door motor opening angle data to the air mix door motor LCU, mode door
motor LCU and intake door motor LCU.
The mode door motor reads their respective signals according to the address signal. Opening angle indication
signals received from the front air control and each of the motor position sensors are compared by the LCU's
in each motor with the existing decision and opening angles. Subsequently, HOT/COLD or DEFROST/VENT
or FRESH/RECIRCULATION operation is selected. The new selection data is returned to the front air control.
COMPONENT DESCRIPTION
Mode Door Motor
The mode door motor is attached to the heater and cooling unit. It
rotates so that air is discharged from the outlet set by the front air
control. Motor rotation is conveyed to a link which activates the mode
door.
DIAGNOSTIC PROCEDURE
SYMPTOM: Mode door motor and/or air mix door motor does not operate normally.
Perform diagnostic procedure for LAN system circuit. Refer to MTC-44, "
LAN System Circuit" .
WJIA0920E
WJIA0042E