ELECTRONICALLY CONTROLLED BRAKE SYSTEM VSC OFF Switch Circuit

DESCRIPTION

The skid control ECU assembly is connected to the combination meter assembly via CAN communication.

Pressing the VSC OFF switch (combination switch assembly) turns off TRC operation, and pressing and holding this switch turns off TRC and VSC operation. If TRC and VSC operations are turned off, the TRC OFF message will be displayed on the multi-information display and the VSC OFF indicator light will come on.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. CHECK CAN COMMUNICATION SYSTEM

   
   

   1. Check if CAN communication system DTCs are output.

      Click here

      Result
      Result Proceed to DTCs are not output. A DTCs are output. B

   
   

   B

   INSPECT CAN COMMUNICATION SYSTEM Click here

   A

2. CHECK IF SKID CONTROL ECU ASSEMBLY CONNECTOR IS SECURELY CONNECTED

   
   

   1. Check if the skid control ECU assembly connector is securely connected.

      OK
      The connector is securely connected.

      Result
      Proceed to OK NG

   
   

   NG

   CONNECT CONNECTOR TO SKID CONTROL ECU ASSEMBLY CORRECTLY

   OK

3. READ VALUE USING GTS (TRC/VSC OFF MODE)

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the power switch on (IG).

   3. Select the Data List on the GTS.

      Click here

      
      Chassis > ABS/VSC/TRC > Data List

      Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
      TRC/VSC Off Mode	TRC/VSC off mode	Normal, TRC OFF, Unknown or VSC OFF	Normal: Normal mode TRC OFF: TRC off mode Unknown: Unspecified VSC OFF: VSC off mode	-

      
      Chassis > ABS/VSC/TRC > Data List

      Tester Display
      TRC/VSC Off Mode

   4. Check the indicator light and mode condition on the GTS changes according to VSC OFF switch (combination switch assembly) operation.

      Standard
      Switch Operation Mode Condition Display Multi-information Display (TRC OFF Message) VSC OFF Indicator Light Not pressed Normal Not displayed Does not come on Pressing the VSC OFF switch (combination switch assembly) TRC OFF Displayed Does not come on Pressing and holding the VSC OFF switch (combination switch assembly) VSC OFF Displayed Comes on

      Result
      Result Proceed to Indicator light and mode condition display do not change. A Mode condition display is normal, but indicator light does not change. B Indicator light and mode condition display is normal. C

   
   

   B

   INSPECT METER / GAUGE SYSTEM Click here

   C

   USE SIMULATION METHOD TO CHECK Click here

   A

4. PERFORM ACTIVE TEST USING GTS (MULTI-INFORMATION DISPLAY AND VSC OFF INDICATOR LIGHT)

   
   

   1. Select the Active Test on the GTS.

      Click here

      
      Chassis > ABS/VSC/TRC > Active Test

      Tester Display	Measurement Item	Control Range	Diagnostic Note
      TRC(TRAC) OFF Indicator Light	Multi-information display (TRC OFF message)	Display ON/OFF	Observe combination meter assembly
      VSC OFF Indicator Light	VSC OFF indicator light	Indicator light ON/ OFF	Observe combination meter assembly

      
      Chassis > ABS/VSC/TRC > Active Test

      Tester Display
      TRC(TRAC) OFF Indicator Light

      
      Chassis > ABS/VSC/TRC > Active Test

      Tester Display
      VSC OFF Indicator Light

   2. Check the multi-information display (TRC OFF message) and VSC OFF indicator light on the combination meter assembly turns ON or OFF in accordance with GTS operation.

      OK
      The multi-information display (TRC OFF message) and VSC OFF indicator light turns ON or OFF in accordance with GTS operation.

      Result
      Proceed to OK NG

   
   

   NG

   INSPECT COMBINATION METER ASSEMBLY Click here

   OK

5. INSPECT COMBINATION SWITCH ASSEMBLY

   
   

   1. Turn the power switch off.

   2. Inspect the VSC OFF switch (combination switch assembly).

      Click here

      OK
      VSC OFF switch (combination switch assembly) is normal.

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE COMBINATION SWITCH ASSEMBLY Click here

   OK

6. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU ASSEMBLY - COMBINATION SWITCH ASSEMBLY)

   
   

   1. Disconnect the A24 skid control ECU assembly connector.

   2. Disconnect the K81 VSC OFF switch (combination switch assembly) connector.

   3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition A24-39 (CSW) - K81-1 (+) Always Below 1 Ω A24-39 (CSW) or K81-1 (+) - Body ground Always 10 kΩ or higher K81-16 (E) - Body ground Always Below 1 Ω

      Tech Tips

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing the parts.

      Click here

      Result
      Proceed to OK NG

   
   

   OK

   REPLACE SKID CONTROL ECU ASSEMBLY for LHD: Click here REPLACE SKID CONTROL ECU ASSEMBLY for RHD: Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

7. INSPECT COMBINATION METER ASSEMBLY

   
   

   1. Turn the power switch off.

   2. Perform the Active Test of the combination meter assembly (meter CPU) using the GTS.

      Click here

      
      Body Electrical > Combination Meter > Active Test

      Tester Display
      Meter Display 1

      
      Body Electrical > Combination Meter > Active Test

      Tester Display
      Indicat. VSC OFF

   3. Check the combination meter assembly.

      OK
      The multi-information display and VSC OFF indicator light turns on or off in accordance with GTS operation.

      Tech Tips

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing the parts.

      Click here

      Result
      Proceed to OK NG

   
   

   OK

   REPLACE SKID CONTROL ECU ASSEMBLY for LHD: Click here REPLACE SKID CONTROL ECU ASSEMBLY for RHD: Click here

   NG

   INSPECT METER / GAUGE SYSTEM Click here