Speed Signal Circuit: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Body Electrical / HL Auto Leveling / Data List.
5. Read the display on the Techstream.
   HL AUTO LEVELING
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Vehicle Speed	Vehicle speed/0 to 327.67 km/h (203.61 mph)	Condition can be displayed	-

   OK

   Normal condition listed above is displayed.

NG → See step   2 

OK → See step   4 

1. Check the output waveform.
   Fig 1: Inspecting Combination Meter Assembly (No. 3 Meter Circuit Plate) Connector Terminals & Waveform

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Remove the combination meter assembly (No. 3 meter circuit plate) with the connector still connected.
   2. Connect an oscilloscope to terminal L27-7 (+S) and body ground.
   3. Turn the power switch on (IG).
   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	Driving at approx. 20 km/h (12 mph)

      OK

      The waveform is displayed as shown in the illustration.

      TEXT IN ILLUSTRATION
      
      

      *a	F with harness connected (Combination Meter Assembly (No. 3 Meter Circuit Plate))

      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: Go to next step 

1. Disconnect the L27 combination meter assembly connector.
2. Disconnect the A96 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
   A96-16 (SPDR) - L27-7 (+S)	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   6