Inspection Procedure

1. Check the DATA LIST for proper functioning of the vehicle speed signal.

   Skid control ECU 

   SKID CONTROL ECU DATA LIST
   
   

   Item	Measurement Item / Range (Display)	Normal Condition	Diagnostic Note
   (FR/FL/RR/RL) SPD	Vehicle speed / Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph)	Almost same as actual speed (When driving)	-

   OK: Vehicle speed displayed on the tester is almost the same as the actual vehicle speed. 

NG: GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM 

OK: GO TO NEXT STEP 

1. Using an oscilloscope, check the signal waveform of the meter.
   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester Connection	Tool Setting	Vehicle Condition
   C10-9 - Body ground	5 V/DIV., 20 msec./DIV.	Driving at approx. 20 km/h (12 mph)

   OK: Refer to the illumination. 

   HINT:

   As the vehicle speed increases, the wavelength shortens.

OK: REPLACE COMBINATION METER 

Fig 1: Identifying C10-9 Combination Meter

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: GO TO NEXT STEP 

1. Disconnect the S8 ECU connector.
2. Disconnect the C10 meter connector.
3. Measure the resistance of the wire harness side connectors.

   Standard resistance 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester Connection	Specified Condition
   C10-9 - S8-22 (SP1)	Below 1 Ω
   C10-9 - Body ground	10 kΩ or higher

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

Fig 2: Identifying S8 ECU And C10 Meter Connector Terminal

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM