Meter / Gauge System Malfunction In Speedometer

WIRING DIAGRAM

INSPECTION PROCEDURE

PERFORM ACTIVE TEST BY INTELLIGENT TESTER

READ VALUE OF INTELLIGENT TESTER

READ VALUE OF INTELLIGENT TESTER

INSPECT COMBINATION METER

CHECK HARNESS AND CONNECTOR (COMBINATION METER - SKID CONTROL ECU)

INSPECT SKID CONTROL ECU

WIRING DIAGRAM

INSPECTION PROCEDURE

1. Operate the intelligent tester according to the display and select the "Active Test".
   
   

   Combination meter:

   
   

   Item	Test Details	Diagnostic Note
   Speed Meter Operation	0 / 40 (24) / 80 (48) / 120 (72) / 160 (96) / 200 (120) / 240 (149) km/h (mph)	-

   OK:

   Needle indication is normal.
   

1. Operate the intelligent tester according to the display and select the "Data List".
   
   

   Combination meter:

   
   

   Item	Measurement Item / Range (Display)	Normal Condition	Diagnostic Note
   Vehicle Speed Meter	Vehicle speed / Min.: 0 km/h (0 mph), Max.: 255 km/h (158 mph)	Almost same as actual vehicle speed (When driving)	-

   OK:

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

1. Operate the intelligent tester according to the display and select the "Data List".
   
   

   Skid control ECU:

   
   

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

   OK:

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

1. Check the input signal waveform.
   

   1. Remove the combination meter with the connector still connected.
      

   2. Connect the oscilloscope to the terminals L31-29 and body ground.
      

   3. Start the engine.
      

   
   
   

   4. Check the signal waveform of the connector.
      

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

      OK:

      As shown in the illustration
      

      HINT:

      As vehicle speed increases, the cycle of the signal waveform narrows.

1. 3UZ-FE:
   

   1. Disconnect the L31 meter connector.
      

   2. Disconnect the A13 meter connector.
      

   3. Measure the resistance of the wire harness side connectors.
      

      Standard resistance:

      Tester Connection	Condition	Specified Condition
      L31-29 - A13-7	Always	Below 1 Ω
      L31-29 - Body ground	Always	10 kΩ or higher

2. 3GR-FE, 3GR-FSE:
   

   1. Disconnect the L31 meter connector.
      

   2. Disconnect the A48 meter connector.
      

   3. Measure the resistance of the wire harness side connectors.
      

      Standard resistance:

      Tester Connection	Condition	Specified Condition
      L31-29 - A48-12	Always	Below 1 Ω
      L31-29 - Body ground	Always	10 kΩ or higher

1. 3UZ-FE:
   

   
   
   

   1. Disconnect the A13 ECU connector.
      

   2. Measure the voltage of the wire harness side connector.
      

      Standard voltage:

      Tester Connection	Condition	Specified Condition
      A13-7 - Body ground	Engine switch on (IG)	10 to 14 V

2. 3GR-FE, 3GR-FSE:
   

   
   
   

   1. Disconnect the A48 ECU connector.
      

   2. Measure the voltage of the wire harness side connector.
      

      Standard Voltage:

      Tester Connection	Condition	Specified Condition
      A48-12 - Body ground	Engine switch on (IG)	10 to 14 V