My 2004 toyota sienna with a single climate control for front cabin control, blows heat only on the driver's side and cold air blows on the passenger side. What could be wrong and how can it be fixed? Thank you
I would suggest starting with checking for trouble codes. Passenger and driver each has their own air mix actuator and the side that is not working correctly should have a fault with it.
1. LIST OF OPERATION METHODS
By operating each of the A/C control switches as shown in the below diagram, 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.
NOTE: 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.