Toyota Sienna Service Manual: Open or Short Circuit in ABS Motor Relay Circuit

DESCRIPTION

The ABS motor relay supplies power to the ABS pump motor. While the ABS & TRAC & VSC are activated, the ECU switches the ABS motor relay ON and operates the ABS pump motor.

WIRING DIAGRAM

INSPECTION PROCEDURE

1 PERFORM ACTIVE TEST USING INTELLIGENT TESTER (ABS MOTOR RELAY)

(a) Connect the intelligent tester to the DLC3.

(b) Start the engine.

(c) Select the ACTIVE TEST mode on the intelligent tester.

ABS / VSC:

(d) Check the operation sound of the ABS motor individually when operating it with the intelligent tester.

OK: Operation sound of the ABS motor should be heard.

REPLACE BRAKE ACTUATOR ASSEMBLY

2 INSPECT NO. 5 RELAY BLOCK (POWER SOURCE TERMINAL)

(a) Remove the VSC MTR relay from the No. 5 R/B.

(b) Turn the ignition switch to the ON position.

(c) Measure the voltage according to the value(s) in the table below.

Standard voltage

3 INSPECT ABS MOTOR RELAY (VSC MTR)

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

Standard resistance

(b) Apply battery positive voltage between terminals 1 and 2.

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

Standard resistance

4 CHECK HARNESS AND CONNECTOR (ABS MOTOR RELAY - SKID CONTROL ECU)

(a) Check for open or short circuit in harness and connector between the ABS motor relay and skid control ECU.

5 RECONFIRM DTC

(a) Clear the DTCs.

(b) Drive the vehicle at a speed of 6 km/h (4 mph) or more.

(c) Check if the same DTCs are recorded (See page BC- 82).

Result

HINT:

• The skid control ECU inspects the motor relay circuit when the stop light switch is turned off and the vehicle is running at a speed of 6 km/h (4mph) or more.
• It is suspect that the DTCs output was caused by the poor connection of the connector terminal.

REPLACE BRAKE ACTUATOR ASSEMBLY

6 INSPECT ABS 1 FUSE

(a) Remove the ABS 1 fuse from the FL block.

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

Standard resistance

7 INSPECT ABS MOTOR RELAY (VSC FAIL)

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

Standard resistance

(b) Apply battery positive voltage between terminals 1 and 2.

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

Standard resistance

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPAIR OR REPLACE HARNESS OR CONNECTOR