Lexus ES: VSC OFF Switch Circuit

DESCRIPTION

The skid control ECU (brake booster with master cylinder assembly) is connected to the combination meter assembly via CAN communication.

Pressing the VSC OFF switch turns off TRAC operation, and pressing and holding this switch turns off TRAC and VSC operation. If TRAC and VSC operations are turned off, the "Traction Control Turned Off" will be displayed on the multi-information display and the VSC OFF indicator light will come on.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

After replacing the skid control ECU (brake booster with master cylinder assembly), perform linear solenoid valve offset learning, ABS holding solenoid valve learning, yaw rate and acceleration sensor zero point calibration and system information memorization after performing "Reset Memory".

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PROCEDURE

1.	CHECK CAN COMMUNICATION SYSTEM

(a) Check if CAN communication system DTCs are output.

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

B

INSPECT CAN COMMUNICATION SYSTEM

A

2.	CHECK IF BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY CONNECTOR IS SECURELY CONNECTED

(a) Check if the skid control ECU (brake booster with master cylinder assembly) connector is securely connected.

OK:

The connector is securely connected.

NG

CONNECT CONNECTOR TO BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY CORRECTLY

OK

3.	READ VALUE USING TECHSTREAM (TRAC/VSC OFF MODE)

(a) Select the Data List on the Techstream.

Click here

Chassis > ABS/VSC/TRAC > Data List

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

Chassis > ABS/VSC/TRAC > Data List

Tester Display
TRAC/VSC Off Mode

(b) Check the indicator light and mode condition on the Techstream changes according to VSC OFF switch operation.

Standard:

Switch Operation	Mode Condition Display	Multi-information Display (Traction Control Turned Off)	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	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

C

USE SIMULATION METHOD TO CHECK

A

4.	PERFORM ACTIVE TEST USING TECHSTREAM (MULTI-INFORMATION DISPLAY (TRACTION CONTROL TURNED OFF) AND VSC OFF INDICATOR LIGHT)

(a) Select the Active Test on the Techstream.

Click here

Chassis > ABS/VSC/TRAC > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
TRC(TRAC) OFF Indicator Light	Multi-information display (Traction Control Turned Off)	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/TRAC > Active Test

Tester Display
TRC(TRAC) OFF Indicator Light

Chassis > ABS/VSC/TRAC > Active Test

Tester Display
VSC OFF Indicator Light

(b) Check the multi-information display (Traction Control Turned Off) and VSC OFF indicator light on the combination meter assembly turn on or off in accordance with Techstream operation.

OK:

The multi-information display (Traction Control Turned Off) and VSC OFF indicator light turn on or off in accordance with Techstream operation.

NG

GO TO STEP 7

OK

5.	INSPECT VSC OFF SWITCH

(a) Turn the power switch off.

*a Component without harness connected (VSC OFF Switch)

(b) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

(c) Disconnect the H13 VSC OFF switch connector.

(d) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
2 (+) - 7 (E)	Switch pushed	Below 1 Ω
2 (+) - 7 (E)	Switch not pushed	10 kΩ or higher

NG

REPLACE VSC OFF SWITCH

OK

6.	CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - VSC OFF SWITCH)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

(b) Disconnect the A45 skid control ECU (brake booster with master cylinder assembly) connector.

(c) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A45-18 (CSW) - H13-2 (+)	Always	Below 1 Ω
A45-18 (CSW) or H13-2 (+) - Body ground	Always	10 kΩ or higher
H13-7 (E) - Body ground	Always	Below 1 Ω

OK

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.	INSPECT COMBINATION METER ASSEMBLY

(a) Perform the Active Test of the combination meter assembly (meter CPU) using the Techstream.

Click here

Body Electrical > Combination Meter > Active Test

Tester Display
Multi Display All (White)

Body Electrical > Combination Meter > Active Test

Tester Display
VSC OFF Indicator

(b) Check the combination meter assembly.

OK:

The multi-information display and VSC OFF indicator light turn on or off in accordance with Techstream operation.

OK

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

NG

INSPECT METER / GAUGE SYSTEM

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