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.

INSPECT CAN COMMUNICATION SYSTEM
1. Using a Techstream, check for DTCs and confirm that there are no problems in the CAN communication system.
  OK: DTCs are not output.
NG: GO TO CAN COMMUNICATION

OK: Go to Next Step

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 "IG Power Supply" in the Data List and read the value displayed on the Techstream.

EMPS:

EMPS DATA LIST REFERENCE

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
IG Power Supply	ECU power source voltage: Minimum: 0 V, Maximum: 20.1531 V	11 to 14 V: Ignition switch ON	-

OK: The normal condition value is displayed on the Techstream.

HINT:

If the voltage is not standard value, inspect the IG power source circuit.

NG: INSPECT POWER SOURCE CIRCUIT (IG) (See INSPECTION PROCEDURE )

OK: Go to Next Step

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

Disconnect the connectors from the power steering ECU.

Measure the voltage and the resistance.

Standard

VOLTAGE AND RESISTANCE SPECIFICATION

Tester Connection	Condition	Specified Condition
IG (D31-6) - Body ground	Ignition switch on	11 to 14 V
PGND (A19-2) - Body ground	Always	Below 1 Ω

Fig 1: Identifying A19 And D31 Power Steering ECU Connector

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to Next Step

REPLACE POWER STEERING ECU
NOTE: After replacing the power steering ECU, perform the torque sensor zero point calibration.
CHECK PS WARNING LIGHT (COMBINATION METER)
1. Check that the P/S warning light on the combination meter does not come on.
  OK: The P/S warning light does not come on.
NG: REPLACE COMBINATION METER

OK: END