Reading Diagnostic Trouble Codes

NOTE: This is the only information provided by the manufacturer for reading diagnostic trouble codes for this system.




1. WARNING FOR A/C COMPRESSOR LOCK

If compressor lock occurs during A/C operation, the A/C switch indicator on the A/C control assembly starts blinking.

When this occurs, check for compressor lock (DTC B1422) using diagnosis trouble code check then proceed to inspect the circuit or the component.

Compressor lock sensor circuit. (See DTC B1422 Compressor Lock Sensor Circuit)




2. LIST OF OPERATION METHODS

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

3. INDICATOR CHECK




a. Turn the ignition switch on while pressing the A/C control AUTO switch and R/F SW simultaneously.




b. Check that all the indicators light up and go off at 1 second intervals 4 times in succession.

HINT: After the indicator check is ended, the diagnostic trouble code check begins automatically.
Press the OFF switch when desiring to cancel the check mode.

4. DTC CHECK (SENSOR CHECK)




a. Perform an indicator check. After the indicator check is completed, the system enters the DTC check mode automatically.

b. Read the DTC displayed on the panel. Refer to the list of DTCs when reading the DTCs (DTCs are output at the temperature display.).

If the slower display is desired, press the Driver Side Temperature Control Switch and change it to step operation. Each time the Driver Side Temperature Control switch is pressed, the display changes by 1 step.






HINT: W/EMV only
If the buzzer sounds when a DTC is being read, it means the trouble indicated by that DTC continues to occur.
If the buzzer does not sound when a DTC is being read, it means the trouble indicated by that DTC occurred earlier (such as poor connector contacts, etc.).




5. DTC CHECK USING LEXUS HAND-HELD TESTER

a. Hook up the LEXUS hand-held tester to the DLC3.
b. Read the diagnostic trouble codes by following the prompts on the tester screen.

Please refer to the LEXUS hand-held tester operator's manual for further details.


6. ACTUATOR CHECK




a. After entering the sensor check mode, press the R/F switch.

b. Since each damper, motor and relay automatically operates at 1 second intervals beginning in order from 20 in the temperature display, check the temperature and air flow visually and by hand.

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









HINT: The buzzer sounds when the display trouble code changes.
Code are displayed in order from the smaller to the larger numbers.
To cancel the check mode, press the Off switch.