Vehicle Speed Signal Circuit between Stereo Component Amplifier and Combination Meter (To 8/2009): Procedure

1. Check the output waveform.
   Fig 1: Identifying Terminal F15

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Remove the combination meter assembly with the connector still connected.
   2. Connect an oscilloscope to terminal F15-3 (+S) and body ground.
   3. Turn the engine switch on (IG).
   4. Turn the wheel slowly.
   5. Check the signal waveform according to the condition(s) in the table below.

      Item	Condition
      Tool setting	5 V/DIV., 20 ms./DIV.
      Vehicle condition	Driving at approx. 20 km/h (12 mph)

      OK

      The waveform is displayed as shown in the illustration.

      HINT: 

      When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows.

      TEXT IN ILLUSTRATION
      
      

      *1	Component with harness connected (Combination Meter Assembly)

NG → See step   4 

OK: Go to next step 

1. Disconnect the stereo component amplifier assembly and combination meter assembly connectors.
   Fig 2: Identifying Stereo Component Amplifier Assembly And Combination Meter Assembly Connectors

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   O33-11 (SPD) - F15-3 (+S)	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *1	Front view of wire harness connector (to Stereo Component Amplifier Assembly)
   *2	Front view of wire harness connector (to Combination Meter Assembly)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   3