Speed Signal Circuit [09/2014 - ]: Procedure

1. The circuits that send vehicle speed signals to this system are inspected in the meter section. Refer to Speed Signal Circuit [09/2014 - ] .
2. During inspection for the meter system, if there is an instruction that indicates to go back to inspections for the lighting system, proceed to the next step.

NEXT: Go to next step 

1. Disconnect the I18 combination meter assembly connector.
2. Disconnect the A34 headlight leveling ECU assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A34-16 (SPDR) - I18-9 (+S)*1	Always	Below 1 Ω
   A34-16 (SPDR) - I18-3 (+S)*2	Always	Below 1 Ω

   • *1: w/o Multi-information Display
   • *2: w/ Multi-information Display

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Check the output waveform.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   1. Remove the combination meter assembly with the connector still connected.
   2. Connect an oscilloscope to terminal I18-9 (+S)*1 or I18-3 (+S)*2 and body ground.
      • *1: w/o Multi-information Display
      • *2: w/ Multi-information Display
   3. Turn the ignition switch to ON.
   4. 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	Wheel being rotated

      OK

      The waveform is displayed as shown in the illustration.

      TEXT IN ILLUSTRATION
      
      

      *A	w/o Multi-information Display
      *B	w/ Multi-information Display
      *a	Component with harness connected (Combination Meter Assembly)

      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.

NG → See step   5 

OK → See step   4