
DESCRIPTION
Each tire pressure warning valve and transmitter measures the internal temperature of its tire as well as tire pressure, and transmits the information to the tire pressure warning ECU along with the transmitter ID.
If the measured temperature is out of the specified range, the tire pressure warning ECU recognizes it as a malfunction, outputs DTCs, and illuminates the tire pressure warning light after blinking for 1 minute.

HINT: It is necessary to perform the procedure to identify the tire pressure warning valve and transmitter that is malfunctioning because it cannot be identified by the output DTC.
INSPECTION PROCEDURE
NOTICE:
1 CHECK TIRES
(a) Check the tire is not flat, and there is no indication of air pressure drop.
OK: Tire is normal.
HINT: If a tire is damaged, the tire pressure warning valve and transmitter may also have been damaged at the same time.


2 IDENTIFY TRANSMITTER CORRESPONDING TO DTC
(a) Set the tire pressure to the specified value.
Cold tire inflation pressure 
(b) Make sure that the ignition switch is off.
(c) Connect the intelligent tester to the DLC3.
(d) Turn the ignition switch to the ON position.
(e) Display the "TIREPRESS" data for each wheel using the intelligent tester.
(f) Rapidly reduce the tire pressure for each wheel at least 40 kPa (0.41 kg/cm2, 5.8 psi) within 30 seconds.
(g) Check the DATA LIST.
TIRE PRESSURE: 
HINT: *: It may take about 5 to 6 minutes until the values are displayed. If the values are not displayed after a few minutes, perform troubleshooting according to the inspection procedure for DTCs C2121/21 to C2124/24 (See page TW-42).
(h) When the "TIREPRESS" data (ID1 to ID4) has changed, repeat this procedure to identify the tire pressure warning valve and transmitter that corresponds to a DTC.
(i) When all of the "TIREPRESS" data (ID1 to ID4) have changed, identify the malfunctioning tire pressure warning valve and transmitter based on the recorded ID numbers and output DTC.
Result 
NOTICE:
3 REPLACE TIRE PRESSURE WARNING VALVE AND TRANSMITTER
(a) Replace the identified tire pressure warning valve and transmitter with a new one (See page TW-84).
HINT:

4 CHECK REGISTRATION OF TRANSMITTER ID
(a) Register the transmitter ID for 4 tires (See page TW-20).

5 PERFORM INITIALIZATION
(a) Perform initialization (See page TW-23).

6 READ VALUE ON INTELLIGENT TESTER
(a) Make sure that the ignition switch is off.
(b) Connect the intelligent tester to the DLC3.
(c) Turn the ignition switch to the ON position.
(d) Select "TIREPRESS" by following the prompts displayed on the intelligent tester.
TIRE PRESSURE:


HINT: *: It may take about 5 to 6 minutes until the values are displayed. If the values are not displayed after a few minutes, perform troubleshooting according to the inspection procedure for DTCs C2121/21 to C2124/24 (See page TW-42).
Result


REPLACE TIRE PRESSURE WARNING ECU (See page TW-87)
Transmitter ID1 Error
Transmitter ID not RegisteredWhen servicing full-time 4wd vehicles
The full-time 4WD SIENNA is equipped with the open
center differential system.
If incorrect preparations or test procedures are used, the
test will not only be unsuccessful, but may be dangerous
as well.
Therefore, before beginning any such servicing or test,
be sure to check the following ...
Rear Air Mix Damper Position Sensor Circuit
DESCRIPTION
This sensor detects the position of the rear air mix control servo motor
(water valve servo motor) and
sends the appropriate signals to the A/C amplifier. The position sensor is built
in the rear air mix control
servo motor (water valve servo motor).
The position sensor's r ...
Input instructions
(a) The general VIN input instructions using the
intelligent tester are shown below:
(b) The arrow buttons (UP, DOWN, RIGHT and LEFT)
and numerical buttons (0 to 9) are used to input the
VIN.
(c) Cursor Operation
To move the cursor around the tester screen, press
the RIGHT and LEFT buttons. ...