Troubleshooting the Climate Control System

[AW, KJ] This procedure comes from the factory shop manual, and puts the air conditioning into a self-test mode where it tells you if any sensors or actuators are broken:

  • Turn the ignition ON.
  • Turn the Fan switch to Auto (all the way counter-clockwise).
  • Set Temp to 18C or 64F and wait one minute or more  (all the way counter-clockwise)
  • Set Temp to 32C or 90F and wait one minute or more  (all the way clockwise)
  • Push ON/OFF and AUTO at the same time
  • And indicator being ON at this time indicates a problem. Read any problems in the LEDs as follows:
Mode Open or shorted in-car temp sensor
Mode, Defrost Symbol Open or shorted ambient temp sensor
Mode, Horizontal Arrow Open or shorted sunlight sensor
Mode, Down Arrow Open or shorted coolant temperature sensor
Mode, Human Figure Open or shorted evaporator temperature sensor
A/C Open or shorted air mix control motor or stuck air mix door
A/C, On Open position signal circuit for mode control motor or mode door stuck
A/C, Off Open position signal circuit for re-circulate control motor
LED on Defrost button Open or shorted circuit for vent control motor or stuck vent control door

Functional check (if you don’t know exactly what’s working or not):

  • Set Fan to Auto.
  • Push and hold both MODE and AUTO while you start the engine

The unit will cycle through the following stages, one stage each 5 seconds:

  • Temperature shown
  • Fan: off low med high max max high med low off
  • Air mix door: open open mid mid closed closed mid mid open open
  • Mode shown: defrst defrst floor horiz+ horiz horiz floor defrst defrst defrst floor +floor +floor
  • Air source: fresh fresh recirc recirc recirc recirc fresh fresh fresh fresh
  • A/C: off on on on on on off off off off

This will tell you if the doors and mode switches are working OK.

Do It Yourself