Inspection Procedure

WARNING: This page is about a different car, the 2008 Toyota Yaris. However, it is still accessible from the selected car via links, so may be relevant.

READ VALUE USING TECHSTREAM

Connect a Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Enter the following menus: Chassis / EMPS / Data List.

Select the item "Motor Actual Current" and "Command Value Current" in the Data List and read the value displayed on the Techstream.

Standard current:

DATA LIST REFERENCE

Data List Item	Steering Position (Left Turned)	Steering Position (Center)	Steering Position (Right Turned)
Motor Actual Current	10 A to 55 A	-1 A to +1 A	-55 A to -10 A
Command Value Current	55 A	0A	-55 A

HINT:

The current changes when steering wheel is turned.

OK: CHECK INTERMITTENT PROBLEMS

NG: Go to Next Step

INSPECT POWER STEERING ECU

Turn the ignition switch on.

Measure the voltage.

Standard voltage

VOLTAGE SPECIFICATION

Tester Connection	Condition (Steering Position)	Specified Condition
M1(b1-1) - PGND(A19-2)	Turned to right	Below 1 V
M1(b1-1) - PGND(A19-2)	Turned to left	11 to 14 V
M2(b1-2) - PGND(A19-2)	Turned to right	11 to 14 V
M2(b1-2) - PGND(A19-2)	Turned to left	Below 1 V

Fig 1: Identifying Power Steering ECU Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: Go to step 4

NG: Go to Next Step

CHECK HARNESS AND CONNECTOR (POWER STEERING ECU - BODY GROUND)

Disconnect the connector from the power steering ECU.

Measure the resistance and the voltage.

Standard

VOLTAGE AND RESISTANCE SPECIFICATION

Tester Connection	Condition	Specified Condition
PGND (A19-2) - Body ground	Always	Below 1 Ω
PIG (A19-1) - Body ground	Ignition switch on.	11 to 14 V

Fig 2: Identifying A19 Power Steering ECU Connector

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to Next Step

INSPECT STEERING COLUMN ASSEMBLY (POWER STEERING MOTOR)

Disconnect the connector from the power steering ECU.

Measure the resistance.

Standard resistance

RESISTANCE SPECIFICATION

Tester Connection	Condition	Specified Condition
M1 (b1-1) - M2 (b1-2)	Always	0.08 to 0.15 Ω
M1 (b1-1) - Body ground	Always	1 MΩ or higher
M2 (b1-2) - Body ground	Always	1 MΩ or higher

Fig 3: Identifying Power Steering Motor Connector Terminals

NG: REPLACE STEERING COLUMN ASSEMBLY

OK: REPLACE POWER STEERING ECU