2005 Toyota Sienna AC blowing hot air

Hi jcnova63,

Thank you for the donation.

Possible causes are the air mix motor or damper, control panel. Here are procedures to go into diagnostics. Check through and see if you can come up with anything.

PRE-CHECK
1. LIST OF OPERATION METHODS
By operating each of the A/C control switches as shown in Fig. 2 , it is possible to enter the diagnosis check mode.

2. INDICATOR CHECK
a. Turn the ignition switch ON while pressing the A/C control AUTO switch and R/F switch simultaneously.

b. Check that the indicators come on and go off 4 times in succession at 1 second intervals.

HINT:
After the indicator check is completed, the system enters the DTC mode automatically.
Press the OFF switch to cancel the check mode.

3. DTC CHECK (SENSOR CHECK)
a. After the indicator check is completed, the system enters the DTC check mode automatically.
b. Read the codes displayed on the panel. (Trouble code are outputted at the temperature display.)

c. If the slower display is desired, press the DEF switch and change it to the step operation. Each time the DEF switch is pressed, the display changes by 1 step.

4. CLEARING DTC a. To clear diagnostic trouble code, there are 2 ways.
1. During sensor check, press the "DEF" switch and "A/C" switch at the same time.
2. Pull the ECU-B fuse in engine room J/B for 20 seconds or longer to clear the DTC memory.

5. ACTUATOR CHECK

a. After entering the DTC check mode (Sensor Check Mode) press the R/F switch.
b. As each damper, motor and relay automatically operate actuator check at 1 second intervals from step No. 1 to No. 10 continuously, check the temperature and air flow from visual and by hand.

If the slower display is desired, press the DEF switch and change it to step operation. Each time the DEF switch is pressed, the display changes by 1 step.

HINT:
Codes are displayed from the smaller to the larger numbers in order.
To cancel the check mode, press the OFF switch.

There is no self diagnostic for the manual HVAC so you would have to do visual check and testing.

Turn the temp to MAX hot and then slowly turn it to MAX cool and see if there are any changes. Watch the air mis motor to see if it is working at this time. The diagram below shows the position it should be under each condition.

If it does not move to MAX cool, try manual pushing the lever to MAX cool and see if it works. There are 2 motors, one for the driver and passenger.