Page 210 of 4500
Fig. 6: Air Conditioning System Diagram (2 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
1.GENERAL
a. The air conditioning system has the following features:
In compliance with the temperature set at the temperature control switch, the neural network
control calculates the outlet temperature based on the input signals from various sensors. In
addition, corrections in accordance with the signals from the evaporative temperature sensor
and the water temperature sensor are added to control the outlet air temperature.
Controls the front and rear blower motors in accordance with the airflow volume that has
been calculated by the neural network control based on the input signals from various
sensors.
Automatically switches the outlets in accordance with the outlet mode ratio that has been
calculated by the neural network control based on the input signals from various sensors.
Automatically controls the air inlet control damper in accordance with the airflow volume
that has been calculated by the neural network control.
Turns the compressor on/off and controls the discharge capacity based on the signals from
various sensors.
Based on the signals from the ambient temperature sensor, this control calculates the outside
temperature, which is then corrected in the air conditioner ECU, and shown in the multi-
information display in the combination meter.
Switched the rear defogger and outside rear view mirror heaters on for 15 minutes when the
rear defogger switch is switched on. Switched them off if the switch is pressed while they are
operating.
Controls the orientation and the angle of the front center register based on the input signals
from various sensors and on the outlet mode.
Determines whether the clean air filter (for the front A/C) is clogged by monitoring the air
inlets, and airflow volume.
The A/C amplifier automatically controls the air inlets based on the signals from the smog
ventilation sensor.
Improves the air quality by linking the air inlet control damper and the blower motor (for the
rear A/C and air purifier), based on the signals from the exhaust gas sensor and the smoke
sensor.
Checks the sensors in accordance with operation of the air conditioner switches.
2.MODEL POSITION AND DAMPER OPERATION
Page 226 of 4500
Fig. 21: Display Code - Conditions Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
1.DATA LIST
HINT:
From the DATA LIST displayed on the hand-held tester, you can read the values of the displays, sensors,
actuators and so on without parts removal. Reading the DATA LIST as the first STEP of troubleshooting
is one way to shorten labor time.
a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position.
c. From the display on the tester, select the "DATA LIST".
DATA LIST / AIR CONDITIONER:
DATA LIST / AIR CONDITIONER
ItemMeasurement Item / Display
(Range)Normal ConditionDiagnostic
Note
Page 229 of 4500
DATA LIST / ENGINE AND ECT / ALL:
DATA LIST / ENGINE AND ECT / ALL
2.ACTIVE TEST
HINT:
Performing the ACTIVE TEST
using the hand-held tester allows the relays, VSV, actuators and so on to
operate without parts removal. Performing the ACTIVE TEST
as the first STEP of troubleshooting is
one way to shorten labor time.
It is possible to display the DATA LIST on the hand-held tester during the ACTIVE TEST.
a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position.
c. From the display on tester, perform the "ACTIVE TEST
".
ACTIVE TEST / AIR CONDITIONER:
ACTIVE TEST / AIR CONDITIONER
FOOT AIR
LEAKFoot air leak / ON, OFFCustomized value will be displayed-
DESTINATION
Destination / DOMEST, USA,
EUROPE, AUSTRAL,
MIDEAST, NO INFO
Changes with destinations-
REAR SOLAR
SENSRear solar sensor / min.: 0 max.:
255Changes depending on brightness-
NOX GAS SENSEmission gas Nox sensor / min.: 0
max.: 255Increases as the gas amount increases-
ItemMeasurement Item / Display
(Range)Normal ConditionDiagnostic
Note
REG PRESS
SENSRegulator pressure sensor / min.:
0 max.: 255Actual regulator pressure is displayed-
FILTER FLOW
VOLFilter flow volume / min.: 0 max.:
65535Actual filter flow volume is displayed-
REG CTRL
CURRNTRegulator control current / min.: 0
A max.: 255 A--
HUMIDITY
SENSHumidity sensor / min.: 0% max.:
100%Actual room humidity is displayed-
#CODESNumber of Trouble Codes / min.:
0 max.: 255Number of DTCs will be displayed-
ItemMeasurement Item/Display (Range)Normal ConditionDiagnostic Note
A/C SIGA/C signal/ ON or OFFA/C ON: ON-
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HINT:
The followings are the possible items to be customized.
AIR CONDITIONER
AIR CONDITIONER CUSTOMIZE PARAMETERS
SMOK - Body
ground (L14-16
- Body ground)L - Body
groundSmoke sensor
operation signal
Ignition switch ON. Rear A/C switch to
AUTO. By using cigarette smoke. Ignition
switch ON. Rear A/C switch to AUTO. By
not using cigarette smoke.
Above 4.0 V
Below 1.0 V
AUTO - Body
ground (L14-17
- Body ground)W -
Body
groundAuto switch
signal
Ignition switch ON. Rear A/C rear seat
AUTO indicator lights up. Ignition switch
ON. Rear A/C rear seat AUTO indicator
does not light up.
Below 1.0 V 10 to
14 V
RHR - Body
ground (L14-18
- Body ground)V -
Body
groundRear blower
motor operation
signal
Ignition switch ON. Rear A/C manual
mode. Rear A/C blower motor does not
operate. Ignition switch ON. Rear A/C
manual mode. Rear A/C blower motor
speed LO or HI. During actuator check
mode. Display code 0. Display code 2.
10 to 14 V Below
1.0 V 10 to 14 V
Below 1.0 V
RFR - Body
ground (L14-19
- Body ground)Y -
Body
groundRear blower
motor operation
signal
Ignition switch ON. Rear A/C blower
motor speed to except HI. Ignition switch
ON. Rear A/C blower motor speed to HI.
During actuator check mode. Display code
0. Display code 2.
10 to 14 V Below
1.0 V 10 to 14 V
Below 1.0 V
FRS - Body
ground (L14-20
- Body ground)B -
Body
groundExhaust damper
servomotor
operation signal
Ignition switch ON. Front A/C blower
motor operates. Push "FRS" switch.
Ambient temperature below -1 °C Ignition
switch ON. Front A/C blower motor
operates. Push "REC" switch.
10 to 14 V Below
1.0 V
(1)w/ Rear A/C
DISPLAY (ITEM)DEFAULTCONTENTSSETTING
Page 251 of 4500
Fig. 36: Room Temperature Sensor Circuit
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.READ VALUE ON HAND-HELD TESTER
a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position and push the hand-held tester main switch on.
c. Select the item below in the DATA LIST, and read the display on the hand-held tester.
DATA LIST / AIR CONDITIONER:
DATA LIST / AIR CONDITIONER
OK:
The display is as specified in the normal condition.
Result:
ItemMeasure Item/Display (Range)Normal ConditionDiagnostic
Note
ROOM
TEMPRoom temperature sensor / min.: -6.5°C (20.3°F)
max.: 57.25°C (126.95°F)Actual room temperature
is displayed-
Page 252 of 4500
AIR CONDITIONER TEST RESULT
B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
C: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT )
A
2.INSPECT COOLER (ROOM TEMPERATURE SENSOR) THERMISTOR
a. Remove the cooler (room temperature sensor) thermistor.
b. Measure the resistance according to the value (s) in the table below.
Standard:
COOLER (ROOM TEMPERATURE SENSOR) THERMISTOR RESISTANCE
NGA
OK (Checking from the PROBLEM SYMPTOM TABLE)B
OK (Checking from the DTC)C
Tester connectionConditionSpecified condition
A14-1 - A14-210°C (50°F)3.00 to 3.73 kohms
A14-1 - A14-215°C (59°F)2.45 to 2.88 kohms
A14-1 - A14-220°C (68°F)1.95 to 2.30 kohms
A14-1 - A14-225°C (77°F)1.60 to 1.80 kohms
A14-1 - A14-230°C (86°F)1.28 to 1.47 kohms
A14-1 - A14-235°C (95°F)1.00 to 1.22 kohms
A14-1 - A14-240°C (104°F)0.80 to 1.00 kohms
A14-1 - A14-245°C (113°F)0.65 to 0.85 kohms
A14-1 - A14-250°C (122°F)0.50 to 0.70 kohms
A14-1 - A14-255°C (131°F)0.44 to 0.60 kohms
A14-1 - A14-260°C (140°F)0.36 to 0.50 kohms
Page 259 of 4500
Fig. 42: Ambient Temperature Sensor Circuit
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.READ VALUE ON HAND-HELD TESTER
a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position and push the hand-held tester main switch on.
c. Select the item below in the DATA LIST, and read the display on the hand-held tester.
DATA LIST / AIR CONDITIONER:
DATA LIST / AIR CONDITIONER:
OK:
The display is as specified in the normal condition.
ItemMeasurement Item/Display (Range)Normal ConditionDiagnostic
Note
AMBI TEMP
SENSAmbient temperature sensor / min.: -23.3°C (-
9.94°F) max.: 65.95°C (150.71 °F)Actual ambient
temperature is displayed-
Page 260 of 4500
Result:
AIR CONDITIONER TEST RESULT
B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
C: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT )
A
2.INSPECT ECM (TAM - E2)
Fig. 43: ECM Connector Wire Harness View
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
a. Remove the ECM with connectors still connected.
b. Turn the ignition switch to the ON position.
c. Measure the voltage according to the value (s) in the table below.
Standard:
ECM (TAM - E2) VOLTAGE
HINT:
As the temperature increases, the voltage decreases.
Result:
NGA
OK (Checking from the PROBLEM SYMPTOM TABLE)B
OK (Checking from the DTC)C
Tester connectionConditionSpecified condition
E3-18 (TAM) - E5-28 (E2)Ignition switch ON at 25°C (77°F)2.0 +/- 0.2V
E3-18 (TAM) - E5-28 (E2)Ignition switch ON at 40°C (104°F)1.4 +/- 0.2 V
