Section 907 (Air Conditioning System - Diagnostics): Pre-Check

1. If the compressor lock occurs during A/C operation, the A/C switch indicator on the A/C control panel starts blinking. When this occurs, check for compressor lock (DTC 22) using diagnosis trouble code. And then proceed to inspect the circuit or the component.

   DTC 22 COMPRESSOR LOCK SENSOR CIRCUIT 

1. By operating each of the A/C control switches as shown in the diagram below, it is possible to enter the diagnosis check mode.
   Fig 2: Diagnosis Check Mode Flow Chart

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1. Turn the ignition switch to ON while pressing the A/C control "AUTO" switch and "R/F" switch simultaneously.
   Fig 3: Locating Indicator SR-5Grade

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   Fig 4: Locating Indicator Limited Grade

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

   HINT:

   • After the indicator check is completed, the system enters the DTC automatically.
   • Press the OFF switch when canceling the check mode.
   Fig 5: Identifying Blinking Pattern

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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 CHART  when reading the codes. (Trouble codes are output on the temperature display.)
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 6: Checking DTC

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1. Clear DTC memory by one of the following methods.
   1. Method 1:

      During the sensor check, press "DEF" switch and "REAR DEF" switch at the same time.

   2. Method 2:

      Pull the ECU-B fuse in the engine room J/B for 20 sec. or longer.

   Fig 7: Locating ECU-B Fuse

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1. After entering the DTC check mode (Sensor Check Mode), press the R/F switch.
2. Since each damper, motor and relay automatically operates at 1 sec. intervals beginning in order from 10 in the temperature display, check the temperature and air flow visually and by hand.

   If 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.

HINT:

• Code are displayed in order from the smaller to the larger numbers.
• To cancel the check mode, press the OFF switch.

Fig 8: Checking DTC

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Fig 9: Display Code And Condition Reference Chart

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1. Check DLC3.

   The vehicle's ECM uses ISO 9141-2 for communication. The terminal arrangement of DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.

Fig 10: Identifying Connector Terminal DLC3

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HINT:

If your display shows UNABLE TO CONNECT TO VEHICLE when you have connected the cable of the hand-held tester to the DLC3, turned the ignition switch ON and operated the scan tool, there is a problem on the vehicle side or tool side.

• If the communication is normal when the tool is connected to another vehicle, inspect the DLC3 on the original vehicle.
• If the communication is still impossible when the tool is connected to another vehicle, the problem is probably in the tool itself, so consult the Service Department listed in the tool's instruction manual.

HINT:

By the DATA LIST displayed by the Hand-held tester, you can read the value of the switch, sensor, actuator, etc. Without removing any parts. Reading the DATA LIST as a first step of troubleshooting is one of the method to shorten the labor time.

1. Connect the Hand-held tester to the DLC3.
2. Turn the ignition switch ON.
3. According to the display on tester, read the "DATA LIST".