AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System) Back-up Power Source Circuit

DESCRIPTION

This is the back-up power source circuit for the air conditioning amplifier. Power is supplied even when the ignition switch is turned off and is used for functions such as the diagnostic trouble code memory.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. INSPECT FUSE (ECU-B)

   
   

   1. Remove the ECU-B fuse from the engine room No. 1 relay block.

   2. Measure the resistance of the fuse.

      Standard resistance
      Tester Connection Condition Specified Condition ECU-B fuse Always Below 1 Ω

   
   

   NG

   REPLACE FUSE

   OK

2. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BATTERY)

   
   

   1. 

      Disconnect the D33 and D34 amplifier connectors.

   2. Measure the voltage according to the value(s) in the table below.

      Standard voltage
      Tester Connection Condition Specified Condition D33-21 (B) - Body ground Always 11 to 14 V D34-24 (+B2)* - Body ground Always 11 to 14 V

      Tech Tips

      *: w/ Rear Air Conditioning

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BODY GROUND)

   
   

   1. 

      Disconnect the D33 and D34 amplifier connectors.

   2. Measure the resistance according to the value(s) in the table below.

      Standard resistance
      Tester Connection Condition Specified Condition D33-14 (GND) - Body ground Always Below 1 Ω D34-20 (GND2)* - Body ground Always Below 1 Ω

      Tech Tips

      *: w/ Rear Air Conditioning

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

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