VEHICLE STABILITY CONTROL 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 turns off TRC operation, and pressing and holding this switch turns off TRC and VSC operation.

• except Multi-information Display Type:

  If TRC and VSC operations are turned off, the TRC OFF indicator and the VSC OFF indicator lights come on.




• for 4WD:

  When the 4WD control switch (transfer position switch) set to L4, VSC is prohibited and the VSC OFF indicator light turns on.

  w/ Rear Differential Lock:

  When the rear differential is locked, VSC is prohibited, and the VSC OFF and TRC OFF indicator lights turn on.

• for Multi-information Display Type:

  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.




• for 4WD:

  When the 4WD control switch (transfer position switch) set to L4, VSC is prohibited and the VSC OFF indicator light turns on.

  w/ Rear Differential Lock:

  When the rear differential is locked, VSC is prohibited, the VSC OFF indicator turns on and the TRC OFF message is displayed.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. CHECK CAN COMMUNICATION SYSTEM

   
   

   1. Check if CAN communication system DTCs are output.

      for LHD with Central Gateway ECU: Click here

      for RHD with Central Gateway ECU: Click here

      for LHD without Central Gateway ECU: Click here

      for RHD without Central Gateway ECU: Click here

      Result
      Proceed to DTC is not output DTC is output

   
   

   DTC is output

   CHECK CAN COMMUNICATION SYSTEM for LHD with Central Gateway ECU: Click here CHECK CAN COMMUNICATION SYSTEM for RHD with Central Gateway ECU: Click here CHECK CAN COMMUNICATION SYSTEM for LHD without Central Gateway ECU: Click here CHECK CAN COMMUNICATION SYSTEM for RHD without Central Gateway ECU: Click here

   DTC is not output

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

   
   

   1. Check if the skid control ECU assembly (brake actuator assembly) connector is securely connected.

      OK
      The connector is securely connected.

      Result
      Proceed to OK (w/o Rear Differential Lock) OK (w/ Rear Differential Lock) NG

   
   

   OK (w/o Rear Differential Lock)

   GO TO STEP 4 Click here

   NG

   CONNECT CONNECTOR TO SKID CONTROL ECU ASSEMBLY CORRECTLY

   OK (w/ Rear Differential Lock)

3. CHECK FOR DIFFERENTIAL SYSTEM

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the ignition switch to ON.

   3. Turn the GTS on.

   4. Enter the following menus: Powertrain / Four Wheel Drive / Trouble Codes.

   5. Check for DTCs.

      
      Powertrain > Four Wheel Drive > Trouble Codes

      Result
      Proceed to DTCs are not output DTCs are output

   
   

   DTCs are output

   GO TO DIFFERENTIAL SYSTEM (DIAGNOSTIC TROUBLE CODE CHART) Click here

   DTCs are not output

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

   
   

   1. Reconnect the A4 skid control ECU (brake actuator assembly) connector.

   2. Connect the GTS to the DLC3.

   3. Turn the ignition switch to ON.

   4. 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 VSC OFF: VSC off mode	Unknown: Unspecified

      
      Chassis > ABS/VSC/TRC > Data List

      Tester Display
      TRC/VSC Off Mode

   5. Check that the indicator light and mode condition on the GTS change according to VSC OFF switch operation.

      Standard
      except Multi-information Display Type
      Switch Operation Mode Condition Display TRC OFF Indicator Light VSC OFF Indicator Light Not pressed Normal Does not come on Does not come on Pressing the VSC OFF switch TRC OFF Comes on Does not come on Pressing and holding the VSC OFF switch VSC OFF Comes on Comes on
      for Multi-information Display Type
      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 TRC OFF Displayed Does not come on Pressing and holding the VSC OFF switch 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 are normal. C

   
   

   B

   INSPECT METER / GAUGE SYSTEM Click here

   C

   USE SIMULATION METHOD TO CHECK Click here

   A

5. 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	TRC OFF indicator light*1 Multi-information display (TRC OFF message)*2	Indicator light ON/OFF*1 Display ON/OFF*2	Observe combination meter assembly Vehicle condition: Vehicle stopped
      VSC OFF Indicator Light	VSC OFF indicator light	Indicator light ON/OFF	Observe combination meter assembly Vehicle condition: Vehicle stopped

      
      

      • *1: except Multi-information Display Type

      • *2: for Multi-information Display Type

      
      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. except Multi-information Display Type:

      Check the TRC OFF indicator light and VSC OFF indicator light on the combination meter assembly turn ON or OFF in accordance with the GTS operation.

      OK
      The TRC OFF indicator light and VSC OFF indicator light turn ON or OFF in accordance with the GTS operation.

      for Multi-information Display Type:

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

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

      Result
      Proceed to OK NG

   
   

   NG

   INSPECT COMBINATION METER ASSEMBLY Click here

   OK

6. INSPECT VSC OFF SWITCH

   
   

   1. Turn the ignition switch off.

   2. Remove the VSC OFF switch.

      Click here

   3. Inspect the VSC OFF switch.

      Click here

      OK
      The VSC OFF switch operates normally.

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE VSC OFF SWITCH Click here

   OK

7. CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - VSC OFF SWITCH)

   
   

   1. Disconnect the A4 skid control ECU (brake actuator assembly) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition A4-33 (CSW) - G22-6 Always Below 1 Ω A4-33 (CSW) or G22-6 - Body ground Always 10 kΩ or higher G22-3 - Body ground Always Below 1 Ω

      Result
      Proceed to OK NG

   
   

   OK

   REPLACE BRAKE ACTUATOR ASSEMBLY Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

8. INSPECT COMBINATION METER ASSEMBLY

   
   

   1. Turn the ignition switch off.

   2. except Multi-information Display Type:

      Perform the Active Test of the combination meter assembly using the GTS.

      Click here

      
      Body Electrical > Combination Meter > Active Test

      Tester Display
      VSC TRC Indicator

      
      Body Electrical > Combination Meter > Active Test

      Tester Display
      Indicat. VSC OFF

      for Multi-information Display Type:

      Perform the Active Test of the combination meter assembly 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
      except Multi-information Display Type:
      The TRC OFF indicator light turns on or off in accordance with the GTS.
      for Multi-information Display Type:
      The multi-information display and VSC OFF indicator light turns on or off in accordance with the GTS operation.

      Result
      Proceed to OK NG

   
   

   OK

   REPLACE BRAKE ACTUATOR ASSEMBLY Click here

   NG

   INSPECT METER / GAUGE SYSTEM Click here