Section 623 (Air Conditioning System - Diagnostics): Pre-Check

By operating each of the A/C control switches as shown in Fig 1 , it is possible to enter the diagnosis check mode.

Fig 1: Identifying List Of Operation Methods A/C Control Switches Diagram

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1. Turn the ignition switch to the ON position while pressing the AUTO switch and R/F switch of A/C control assembly at the same time.
   Fig 2: Checking Indicator

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2. Check if the indicator light to be on and off at intervals of 1 second for 4 times.

HINT:

• After the indicator check is completed, the system enters the DTC check mode automatically.
• To end the check mode, press the OFF switch.
  Fig 3: Checking Indicator Light To Be On & Off At Intervals Of Second For Times

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1. Perform an indicator check. After the indicator check is completed, the system enters the DTC check mode automatically.
2. Read the code displayed on the panel. Refer to the list of codes on DIAGNOSTIC TROUBLE CODE TABLE  when reading the codes. (Trouble codes are the numbers appear on the temperature display.)
   Fig 4: Performing An Indicator Check

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3. If the slower display is desired, press the FRONT DEF switch and change it to stepped operation. Each time the FRONT DEF switch is pressed, the display changes by 1 step.
   Fig 5: Identifying Front DEF Switch

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1. Clear DTC by one of the following methods.
   1. Method 1: During sensor check, press the "FRONT DEF" switch and "REAR. DEF" switch at the same time.
   2. Method 2: Pull the ECU-B fuse in engine room J/B for 20 sec. or longer to clear the DTC memory.
      Fig 6: Identifying ECU-B Fuse In Engine Room J/B

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1. After entering the DTC check mode (Sensor Check Mode) press the R/F switch.
2. 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 visually 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:

• Code are displayed in order from the smaller to the larger numbers.
• To end the check mode, press the OFF switch.
  Fig 7: Checking Actuator

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