Inspection Procedure

1. Check output value of ECM.
   1. Connect the hand-held tester to DLC3.
   2. Turn the ignition switch to ON and push the hand-held tester main switch to ON.
   3. Select the item "COOLANT TEMP" in the DATA LIST and read its value displayed on the handheld tester.

      OK: Same as actual engine coolant temperature. 

1. NG: GO TO ENGINE CONTROL SYSTEM 
2. OK: Go to next step. 

(REFERENCE) INSPECTION USING OSCILLOSCOPE 

1. Check the input signal waveform.
   1. Remove the combination meter assy with connectors still connected.
   2. Connect the oscilloscope to the terminals C7-11 and C7-1 of combination meter assy.
   3. Start engine.
      Fig 1: Identifying Combination Meter Assy Terminals C7-11 And C7-1

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   4. Check the signal waveform.
      ITEM CONTENTS
      
      

      Item	Contents
      Tool setting	5V/DIV, 100ms/DV
      Vehicle condition	Engine idle speed

      Fig 2: Oscilloscope Signal Waveform Graph

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. OK: CHECK AND REPLACE COMBINATION METER ASSY 
2. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR