Inspection Procedure

1. Remove the combination meter assembly with the connector still connected.
2. Connect an oscilloscope to terminal E55-36 (+S) and body ground.
3. Turn the ignition switch to ON.
4. Turn the wheel slowly.
5. Check the signal waveform according to the condition(s) in the table below.
   ITEM CONDITION REFERENCE CHART
   
   

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

   Fig 1: Identifying E55 Combination Meter Connector With Waveform Graph

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   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.

   NG: GO TO METER / GAUGE SYSTEM  (See METER / GAUGE SYSTEM )

   OK: Go to Next Step 

Standard Resistance 

Fig 2: Identifying E31 Radio Receiver Connector And E55 Combination Meter Assembly Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: REPLACE RADIO RECEIVER  (See REMOVAL  )