On-Vehicle Inspection [09/2014 - ]: Procedure

HINT: 

The signal readings of the semiconductor pwr integration ECU can be checked by inspecting the voltage at the diagnosis terminal.

1. Signal reading check
   1. Turn the engine switch on (IG).
   2. Connect the positive (+) terminal of a voltmeter to the semiconductor pwr integration ECU and the negative (-) terminal to the body ground.

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      *a	Component with harness connected (Semiconductor Pwr Integration ECU)
      *b	Diagnosis Terminal

   3. Using the illustration below as a reference, determine whether any channels are malfunctioning based on the observed signal reading.

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT: 

      • The present signal reading and history signal reading will be displayed alternately after the engine switch is turned on (IG). By measuring the duration of each header, the present signal reading and history signal reading can be recognized.
      • A unit malfunction indicates an internal malfunction of the semiconductor pwr integration ECU. If a malfunction is detected for any channel from channel 0 to 7, an electrical load connected to the semiconductor pwr integration ECU may be malfunctioning or there may be a short in the semiconductor pwr integration ECU circuit or in the wire harness.
      • The present signal reading will be stored as a history signal reading when electrical loads are operated after a malfunctioning part returns to normal.
      • Both present and history signal readings can be cleared by disconnecting the cable from the negative (-) battery terminal.
      • Depending on the specification, different electrical loads connected to channels 0 to 7 are provided. Refer to the table below:

        Channel	Connected Electrical Load
        ch0	-
        ch1	Rear window defogger wire
        ch2	Windshield deicer wire*1
        ch3	-
        ch4	Daytime running lights*2
        ch5	Stop lights
        ch6	High beam headlight RH*2
        ch7	High beam headlight LH*2

      1. *1: w/ Windshield Deicer System
      2. *2: for Single Beam Headlight

1. Results of signal reading check
   1. Depending on the signal reading, perform troubleshooting according to the table below.

      Output Signal Reading	Repair Method
      Normal	Continue troubleshooting for each system.
      The unit is malfunctioning	Replace the semiconductor pwr integration ECU.
      A malfunction in a channel (ch0 to ch7)	Check for a short in the wire harnesses between the semiconductor pwr integration ECU and each electrical load. Inspect each of the electrical loads. Replace the semiconductor pwr integration ECU.

      HINT: 

      Make sure to clear the signal readings by disconnecting the cable from the negative (-) battery terminal after replacement or repair of the malfunctioning part.

   2. If no signal readings are output, perform troubleshooting according to the following troubleshooting procedure.

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      *a

      Component without semiconductor pwr integration ECU (No. 2 Engine Room Relay Block and No. 2 Junction Block Assembly)

      -

      -

      1. Remove the semiconductor pwr integration ECU.

         Refer to REMOVAL [09/2014 - ] 

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

         Standard Voltage

         Tester Connection	Condition	Specified Condition
         2D-11 - Body ground	Engine switch on (IG)	11 to 14 V

         If the result is not as specified, repair or replace the wire harness or connector.