Last Modified: 7-3-2017 6.8:8.0.40 Doc ID: RM000001BTR005X
Model Year Start: 2007 Model: LX470 Prod Date Range: [08/2006 -           ]
Title: BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: VSC TRAC Warning Light Circuit; 2007 MY LX470 [08/2006 -        ]

VSC TRAC Warning Light Circuit

DESCRIPTION

If the ECU stores DTC, the VSC TRAC warning light illuminates the combination meter.

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

  • When using the intelligent tester, start form *1 if the VSC TRAC warning light does not light up, or start form *3 if the VSC TRAC warning light remains on.
  • When not using the intelligent tester, start form *2 if the VSC TRAC warning light does not light up, or start form *4 if the VSC TRAC warning light remains on.

PROCEDURE

1.

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (WARNING LIGHT)*1

(a) Select the ACTIVE TEST, generate a control command, and then check that the VSC TRAC warning light operates.

Skid control ECU

Item

Vehicle Condition / Test Details

Diagnostic Note

VSC TRAC WARN LIGHT

Turn VSC TRAC warning light ON / OFF

Observe combination meter

OK:

VSC TRAC warning light turns on or off.

OK

REPLACE SKID CONTROL ECU ASSEMBLY

NG

2.

CHECK VSC TRAC WARNING LIGHT*2

(a) Disconnect the A40 ECU connector.

(b) Turn the ignition switch ON.

(c) Using a service wire, connect terminal WA to GND3 or GND4 of the A40 ECU connector. Check the VSC TRAC warning light.

OK:

VSC TRAC warning light turns off.

(d) Turn the ignition switch OFF.

(e) Remove the service wire.

(f) Turn the ignition switch ON. Check the VSC TRAC warning light.

OK:

VSC TRAC warning light illuminates.

OK

REPLACE SKID CONTROL ECU ASSEMBLY

NG

3.

INSPECT RELAY (Marking: IG1 NO. 2)

(a) Remove the IG1 NO. 2 relay from the cowl side junction block LH.

(b) Measure the resistance of the relay.

Standard resistance:

Tester Connection

Specified Condition

1 - 2

10 kΩ or higher

1 - 2

Below 1 Ω

(when battery voltage is applied to terminals 3 and 4)
NG

REPLACE RELAY

OK

CHECK COMBINATION METER (COMBINATION METER CIRCUIT)

4.

INSPECT SKID CONTROL ECU CONNECTOR*3

(a) Check that each ECU connector is properly installed.

OK:

Each ECU connector is properly installed.

NG

CONNECT CONNECTOR TO ECU CORRECTLY

OK

5.

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (VSC TRAC WARNING LIGHT)

(a) Select the ACTIVE TEST, generate a control command, and then check that the VSC TRAC warning light operates.

Skid control ECU

Item

Vehicle Condition / Test Details

Diagnostic Note

VSC TRAC WARN LIGHT

Turn VSC TRAC warning light ON / OFF

Observe combination meter

OK:

VSC TRAC warning light turns on or off.

OK

REPLACE SKID CONTROL ECU ASSEMBLY

NG

6.

CHECK FOR DTC*4

(a) Turn the ignition switch ON.

(b) Check that the VSC TRAC warning light illuminates.

(c) Check if the same DTCs are recorded.

Result:

Result

Proceed to

DTC is not output

A

DTC is output

B
B

REPAIR CIRCUIT INDICATED BY OUTPUT DTC

A

7.

CHECK WIRE HARNESS (SKID CONTROL ECU ASSEMBLY - COMBINATION METER)
NG

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK

REPLACE SKID CONTROL ECU ASSEMBLY