Power Steering System (For Hatchback) Ps Warning Light Remains On

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK HARNESS AND CONNECTOR

CHECK CAN COMMUNICATION SYSTEM

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

REPLACE POWER STEERING ECU ASSEMBLY

PERFORM ASSIST MAP WRITING

CHECK EPS WARNING LIGHT

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:

1. If the power steering ECU assembly is replaced, perform the torque sensor zero point calibration and assist map writing (YARIS_NCP93 RM000000OSZ018X.html).
   
2. Inspect the fuses for circuits related to this system before performing the following inspection procedure.
   

HINT:

If the battery is not sufficiently charged or the voltage decreases temporarily, the amount of power assist may be reduced and the EPS warning light may come on. In such cases, the amount of power assist returns to normal when the battery voltage recovers. If the EPS warning light comes on but no DTCs are stored, check the Data List "Battery Voltage Lo Record" (YARIS_NCP93 RM000001AL8022X.html).

1. Turn the ignition switch to ON.
   

2. Check the indication condition of the EPS warning light by wiggling the power steering ECU assembly connector and wire harness up and down, and right and left.
   

   OK:

   EPS warning light indication condition does not change.
   

1. Check for DTCs of the CAN communication system.
   

   Yaw Rate Sensor Type	See Page
   for Hatchback except Separate Type Yaw Rate Sensor	YARIS_NCP93 RM000001RSW02LX.html
   for Hatchback with Separate Type Yaw Rate Sensor	YARIS_NCP93 RM000001RSW02PX.html

   Result

   Result	Proceed to
   DTCs is not output	A
   DTCs is output (for Hatchback except Separate Type Yaw Rate Sensor)	B
   DTCs is output (for Hatchback with Separate Type Yaw Rate Sensor)	C

1. Disconnect the power steering ECU assembly connectors.
   

2. Measure the voltage according to the value(s) in the table below.
   

   Standard Voltage:

   Tester Connection	Switch Condition	Specified Condition
   D104-1 (IG) - Body ground	Ignition switch ON	11 to 14 V

3. Measure the resistance according to the value(s) in the table below.
   

   Standard Resistance:

   Tester Connection	Condition	Specified Condition
   A68-2 (PGND) - Body ground	Always	Below 1 Ω

   Text in Illustration

   *a	Rear view of wire harness connector (to Power Steering ECU Assembly)

1. Replace the power steering ECU assembly (YARIS_NCP93 RM000002XN603ZX.html).
   

1. Perform assist map writing (YARIS_NCP93 RM000000OSZ018X.html).
   

1. Check that the EPS warning light on the combination meter assembly does not come on.
   

   OK:

   The EPS warning light on the combination meter assembly does not come on.