Inspection Procedure

WARNING: This page is about a different car, the 2007 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.

READ VALUE OF INTELLIGENT TESTER (STEERING SENSOR)

Check the DATA LIST for proper functioning of the steering sensor.

AFS ECU

DATA LIST - AFS ECU

Item	Measurement Item / Display (Range)	Normal Condition	Diagnostic Note
STEER SENS SIG	Steering sensor signal value / -384 to 382.5	Condition value will be displayed.	-

OK: Condition value will be displayed.

OK: REPLACE AFS ECU

NG: Go to Next step

CHECK FOR DTC (VEHICLE STABILITY CONTROL SYSTEM)
1. Check for DTCs of the vehicle stability control system (see DTC CHECK / CLEAR ).
  OK: Normal system code is output.
NG: GO TO VEHICLE STABILITY CONTROL SYSTEM

OK: Go to Next step

CHECK WIRE HARNESS (SENSOR - ECU)

Disconnect the S9 sensor connector.
Disconnect the A31 ECU connector.

Fig 1: Identifying Steering Angle Sensor And AFS ECU Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the resistance of the wire harness side connectors.

Standard resistance

RESISTANCE SPECIFICATION

Tester Connection	Specified Condition
S9-7 (SS2-) - A31-8 (SS-)	Below 1 Ω
S9-8 (SS2+) - A31-7 (SS+)	Below 1 Ω
S9-7 (SS2-) - Body ground	10 kΩ or higher
S9-8 (SS2+) - Body ground	10 kΩ or higher

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: Go to Next step

CHECK AFS ECU

Fig 2: Identifying AFS ECU Connector Terminals

Measure the voltage of the connector.

Standard voltage

VOLTAGE SPECIFICATION

Tester Connection	Switch Condition	Specified Condition
A31-7 (SS+) - A31-8 (SS-)	Ignition switch ON	0 to 5 V (Pulse generation)

NG: REPLACE STEERING SENSOR

OK: REPLACE AFS ECU