Inspection Procedure

1. Connect the Techstream to the DLC3.
2. Turn the power switch ON (IG).
3. Clear the DTC.
4. Check for DTC.

   HINT:

   When DTCs other than U0131 are output, inspect and repair the trouble areas indicated by those DTCs first.

   Result 

   DTC OUTPUT RESULT
   
   

   Result	Proceed to
   DTC U0131 is not output	A
   DTC U0131 is output	B

B:  GO TO ELECTRONIC POWER STEERING SYSTEM

A: Go to next step 

1. Disconnect the A23 power steering ECU connector.
2. Measure the resistance of the wire harness side connector.

   Standard resistance 

   RESISTANCE SPECIFIED CONDITION
   
   

   Tester Connection	Condition	Specified Condition
   A23-2 (CANH) - A23-3 (CANL)	Power switch OFF	54 to 69 Ω

Fig 1: Identifying A23 Power Steering ECU Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE POWER STEERING ECU BRANCH WIRE OR CONNECTOR (CANH, CANL) 

OK: Go to next step 

1. Disconnect the A23 power steering ECU connector.
2. Measure the resistance of the wire harness side connector.

   Standard resistance 

   RESISTANCE SPECIFIED CONDITION
   
   

   Tester Connection	Specified Condition
   A23-5 (POND) - Body ground	Below 1 Ω

3. Measure the voltage of the wire harness side connector.

   Standard voltage 

   VOLTAGE SPECIFIED CONDITION
   
   

   Tester Connection	Condition	Specified Condition
   A23-9 (IG) - Body ground	Power switch ON (IG)	10 to 14 V

Fig 2: Identifying A23 Power Steering ECU Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: REPLACE POWER STEERING ECU