Operational Check (Front)
The purpose of the operational check is to confirm that the system operates properly.
Conditions : Engine running and at normal operating temperature
Operational Check (Rear)
The purpose of the operational check is to confirm that the system operates properly.
Conditions : Engine running and at normal operating temperature
DESCRIPTION
The self-diagnostic system diagnoses sensors, CAN system, and battery voltage on A/C auto amp. Refer to applicable procedure (items) for details. Fault codes (if any are present) will be displayed in the ambient temperature display area. Refer to " A/C SYSTEM SELF-DIAGNOSIS CODE CHART ".
System Operation
The mode door position (vent, B/L, foot, D/F, and defrost) is set by the A/C auto amp. by means of the mode door motor (front). When a mode door position is selected on the A/C auto amp., voltage is applied to one circuit of the mode door motor (front) while ground is applied to the other circuit, causing the mode door motor (front) to rotate. The direction of rotation is determined by which circuit has voltage applied to it, and which one has ground applied to it. The A/C auto amp. monitors the mode door position by measuring the voltage signal on the PBR circuit.
In AUTO mode the mode door position is set by the A/C auto amp. which determines the proper position based on inputs from the in-vehicle sensor, ambient sensor, optical sensor, intake sensor, and the temperature selected by the driver or passenger.
Scheme 63
Mode Door Control Specification
Scheme 64
The mode door motor (front) is attached to the heater & cooling unit assembly. It rotates so that air is discharged from the outlet as indicated by the A/C auto amp. Motor rotation is conveyed to a link which activates the mode door.
Scheme 65
The A/C auto amp. receives data from the temperature selected by the driver side, passenger side, and rear. The A/C auto amp. then applies a voltage to one circuit of the appropriate air mix door motor, while ground is applied to the other circuit, causing the appropriate air mix door motor to rotate. The direction of rotation is determined by which circuit has voltage applied to it, and which one has ground applied to it. The A/C auto amp. monitors the air mix door positions by measuring the voltage signal on the PBR circuits of each door.
In AUTO mode the air mix, intake, mode door, and defrost door positions are set by the A/C auto amp. which determines the proper position based on inputs from the in-vehicle sensor, ambient sensor, optical sensor, intake sensor, and the temperature selected by the driver and front and rear passengers.
Subsequently, HOT/COLD or DEFROST/VENT or FRESH/RECIRCULATION operation is selected. The new door position data is returned to the A/C auto amp.
Scheme 66
Scheme 67
The intake door control determines the intake door position based on the position of the recirculation switch. When the recirculation switch is depressed the intake door motor rotates closing off the fresh air inlet and recirculating the cabin air. If the recirculation switch is depressed again, the intake door motor rotates in the opposite direction, again allowing fresh air into the cabin.
In the AUTO mode, the A/C auto amp. determines the intake door position based on the ambient temperature, the intake air temperature and the in-vehicle temperature. When the DEF, D/F, FLOOR or OFF switches are pushed, the A/C auto amp. sets the intake door at the fresh position.
Scheme 68
Scheme 69
The A/C auto amp. determines defroster door position based on the position of the defroster switch. When the defroster switch is depressed, the defroster door motor rotates directing air to the defroster ducts. When any mode other than defroster is selected, the defroster motor rotates in the opposite direction closing off air flow to the defroster ducts.
In the AUTO mode, the A/C auto amp. determines defroster door position based on the ambient temperature, the intake air temperature and the in-vehicle temperature.
Scheme 70
SYSTEM DESCRIPTION
The A/C auto amp. controls compressor operation based on ambient and intake temperature and a signal from ECM.
Low Temperature Protection Control
The A/C auto amp. will turn the compressor ON or OFF as determined by a signal detected by the intake sensor and the ambient sensor.
When intake air temperature is higher than the preset value, the compressor turns ON. The compressor turns OFF when intake air temperature is lower than the preset value. That preset value is dependent on the ambient temperature, refer to the following table.
| Ambient temperature °C (°F) | Compressor ON intake temperature °C (°F) | Compressor OFF intake temperature °C (°F) |
|---|---|---|
| 0 (32) | 5.5 (42) | 5.0 (41) |
| 10 (50) | 5.5 (42) | 5.0 (41) |
| 20 (68) | 5.5 (42) | 5.0 (41) |
| 30 (86) | 4.0 (39) | 3.5 (38) |
| 40 (104) | 3.5 (38) | 3.0 (37) |
| 50 (122) | 3.5 (38) | 3.0 (37) |
AMBIENT TEMPERATURE CHART
COMPONENT DESCRIPTION
The optical sensor (1) is located in the center of the defroster grille. It detects sunload entering through windshield by means of a photo diode. The sensor converts the sunload into a current value which is then input into the A/C auto amp.
Scheme 71
OPERATION PROCEDURE
- Connect both battery cables. NOTE: Supply power using jumper cables if battery is discharged.
- Use the Intelligent Key or mechanical key to turn the ignition switch to the "ACC" position. At this time, the steering lock will be released.
- Disconnect both battery cables. The steering lock will remain released and the steering wheel can be rotated.
- Perform the necessary repair operation.
- When the repair work is completed, return the ignition switch to the "LOCK" position before connecting the battery cables. (At this time, the steering lock mechanism will engage.)
- Perform a self-diagnosis check of all control units using CONSULT-III.
See also:
• DISPLAY UNIT
• DIAGNOSIS PROCEDURE