Inspection Procedure

1. CHECK HARNESS AND CONNECTOR 
   1. Check the indication condition of the P/S warning light while wiggling the power steering ECU assembly connector and wire harness up and down, and right and left.

      OK: P/S warning light indication condition does not change. 

      NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

      OK: Go to next Step 

2. INSPECT CAN COMMUNICATION SYSTEM 
   1. Using the 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 SYSTEM  (See HOW TO PROCEED WITH TROUBLESHOOTING )

      OK: Go to next Step 

3. INSPECT MULTIPLEX COMMUNICATION SYSTEM 
   1. Using the Techstream, check for DTCs and confirm that there are no problems in the multiplex communication system (BEAN).

      OK: DTCs are not output. 

      NG: GO TO MULTIPLEX COMMUNICATION SYSTEM  (See DIAGNOSTIC TROUBLE CODE CHART )

      OK: Go to next Step 

4. INSPECT FUSE 
   1. Remove the ECU-IG LH fuse from the cowl side junction block LH
   2. Measure the resistance according to the value (s) in the table below.

      Standard Resistance 

   TESTER CONNECTION SPECIFIED CONDITION REFERENCE CHART
   
   

   Tester Connection	Condition	Specified Condition
   ECU-IG LH fuse	Always	Below 1 Ω

   NG: REPLACE FUSE 

   OK: Go to next Step 

5. CHECK HARNESS AND CONNECTOR (POWER STEERING ECU ASSEMBLY - BATTERY) 
   1. Disconnect the A31 connector from the power steering ECU assembly
   2. Measure the voltage according to the value (s) in the table below

      Standard Voltage 

   TESTER CONNECTION SPECIFIED CONDITION REFERENCE CHART
   
   

   Tester Connection	Switch Condition	Specified Condition
   A31-9 (IG) - Body ground	Engine switch on (IG)	11 to 14 V

   Fig 1: Identifying A31 Power Steering ECU Assembly Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK: Go to next Step 

6. CHECK HARNESS AND CONNECTOR (POWER STEERING ECU ASSEMBLY - BODY GROUND) 
   1. Measure the resistance according to the value (s) in the table below

      Standard Resistance 

   TESTER CONNECTION SPECIFIED CONDITION REFERENCE CHART
   
   

   Tester Connection	Condition	Specified Condition
   A31-5 (PGND) - Body ground	Always	Below 1 Ω

   Fig 2: Identifying Power Steering ECU Assembly Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK: Go to next Step 

7. INSPECT COMBINATION METER ASSEMBLY 
   1. Turn the engine switch off
   2. Connect the Techstream to the DLC3
   3. Turn the engine switch on (IG)
   4. Turn the Techstream on
   5. Perform the Active Test according to the display on the Techstream Enter the following menus: Body Electrical / Combination Meter / Active Test

      Combination Meter 

OK: P/S warning light comes on. 

NG: REPLACE COMBINATION METER ASSEMBLY  (See REMOVAL )

OK: REPLACE POWER STEERING ECU ASSEMBLY  (See POWER STEERING ECU )