Inspection Procedure

1. Select the ACTIVE TEST, use the hand-held tester to generate a control command and then check that the tachometer operates.

   Combination meter assy: 

   TACHOMETER
   
   

   Item	Test Details	Diagnostic Note
   TACHOMETER	Tachometer operation (rpm) 0/1000/2000/3000/4000/5000/6000/7000	Confirm that vehicle is stopped and engine is idling

   OK: The meter operates normally. 

1. NG: REPLACE COMBINATION METER ASSY (See  COMBINATION METER ASSY  ) 
2. OK: Go to next step. 

1. Check the DATA LIST for proper functioning of the tachometer.

   Combination meter assy: 

   Fig 1: Tachometer Data List Table

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: Engine speed on tester is almost equal to the actual engine speed. 

1. NG: Go to step   3 
2. OK: REPLACE COMBINATION METER ASSY (See  COMBINATION METER ASSY  ) 

1. Using an oscilloscope, check the signal waveform of the ECM.

   Standard: 

   ECM (TACH)
   
   

   Tester Connection	Tester Range	Vehicle Condition
   E5-16 (TACH) - E3-7 (E1)	10 V/DIV., 20 msec./DIV.	Engine idling

   OK: As shown in  Fig 2 

HINT:

• As the engine speed increases, the wavelength shortens.
• Connect the tester's positive (+) lead to TACH terminal and negative (-) lead to E1 terminal.
  Fig 2: Checking ECM (Tach)

  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. NG: Go to  SFI SYSTEM - DIAGNOSTICS 
2. OK: Go to next step. 

1. Using an oscilloscope, check the signal waveform of the meter.

   Standard: 

   COMBINATION METER ASSY
   
   

   Tester Connection	Tester Range	Vehicle Condition
   C8-4 (S) - Body ground	10 V/DIV., 20 msec./DIV.	Engine idling

   OK: As shown in  Fig 3 

   HINT:

   As the vehicle speed increases, the wavelength shortens.

   Fig 3: Checking Combination Meter Assy

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 
2. OK: REPLACE COMBINATION METER ASSY (See  COMBINATION METER ASSY  )