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IG Power Source Circuit: Procedure

WARNING: This page is about a different car, the 2011 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.
  1. INSPECT AIR CONDITIONING AMPLIFIER (IG+ - GND) 
    1. Remove the A/C amplifier with its connectors still connected.
      Fig 1: Identifying E30 Connector GND & IG+ Terminals
      GTY292100Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Turn the ignition switch to ON.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      E30-1 (IG+) - E30-14 (GND) Ignition switch ON 11 to 14 V
      TEXT IN ILLUSTRATION

      *a Component with harness connected
      (A/C Amplifier)

    NG → See step   2 

    OK → See step   4 

  2. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BATTERY) 
    1. Disconnect the connector from the A/C amplifier.
      Fig 2: Identifying E30 Connector IG+ Terminal
      GTY293803Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      E30-1 (IG+) - Body ground Ignition switch off Below 1 V
      Ignition switch ON 11 to 14 V
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to A/C Amplifier)

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BODY GROUND) 
    1. Measure the resistance according to the value(s) in the table below.
      Fig 3: Identifying E30 Connector GND Terminal
      GTY291439Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Condition Specified Condition
      E30-14 (GND) - Body ground Always Below 1 Ω
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to A/C Amplifier)

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   5 

  4. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE 
  5. REPLACE AIR CONDITIONING AMPLIFIER. Refer to  REMOVAL