FAIL-SAFE FUNCTION
If a communication error exists between the A/C auto amp., and the AV control unit and preset switch for 30 seconds or longer, air conditioning is controlled under the following conditions
When ambient temperature is less than 3°C (37°F) and engine coolant temperature is less than 56°C (133°F)
Compressor: ON
Air outlet: DEF
Air inlet: FRE (Fresh air intake)
Blower fan speed: AUTO
Set temperature: Setting before communication error occurs
When ambient temperature is 3°C (37°F) or more, or engine coolant temperature is 56°C (133°F) or more
Compressor: ON
Air outlet: AUTO
Air inlet: 20% FRE (20% fresh air intake)
Blower fan speed: AUTO
Set temperature: Setting before communication error occurs
Scheme 273
- A/C auto amp. controls passenger room temperature so that the optimum level always matches the temperature level that passenger may feel. Correction is applied to the target temperature that is set using temperature control dial, according to ambient temperature detected by ambient sensor.
- A/C auto amp. performs correction to change recognition intake temperature of A/C auto amp. quickly when difference is large between recognition intake temperature and intake temperature detected by intake temperature sensor. The correction is performed to change recognition intake temperature slowly when difference is small.
- Sunload amount detected by sunload sensor is corrected for each rear automatic air conditioning control.
- A/C auto amp. performs correction to change recognition sunload amount of A/C auto amp. slowly when sunload amount changes quickly, for example when entering or exiting a tunnel.
If the engine coolant temperature is 56°C (133°F) or less, to prevent a cold discharged air flow, A/C auto amp. suspends rear blower motor activation for the maximum 150 seconds depending on target air mix door (rear) opening angle. After this, rear blower motor control signal is increased gradually, and rear blower motor is activated.
Scheme 274
When front evaporator fin temperature is high [intake sensor value is 35°C (95°F) or more], to prevent a hot discharged air flow, A/C auto amp. suspends rear blower motor activation for approximately 3 seconds so that rear evaporator is cooled by refrigerant.