POWER STEERING SYSTEM PS Warning Light Remains ON

DESCRIPTION

The power steering ECU assembly is connected to the combination meter via CAN and multiplex communications. If any of the following is detected, the P/S warning light remains on.

• The power steering ECU assembly connectors are disconnected from the power steering ECU assembly.

• There is a malfunction in the power steering ECU assembly internal circuit.

• There is an open in the harness between the combination meter and power steering ECU assembly.

When a voltage source drop is occurred in a system, the warning light comes on to inform the driver of the problem.

WIRING DIAGRAM

INSPECTION PROCEDURE

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

2. INSPECT CAN COMMUNICATION SYSTEM

   
   

   1. Using the intelligent tester, 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 Click here

   OK

3. INSPECT MULTIPLEX COMMUNICATION SYSTEM

   
   

   1. Using the intelligent tester, 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 Click here

   OK

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

   
   

   NG

   REPLACE FUSE

   OK

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

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

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

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

7. INSPECT COMBINATION METER ASSEMBLY

   
   

   1. Turn the engine switch off.

   2. Connect the intelligent tester to the DLC3.

   3. Turn the engine switch on (IG).

   4. Turn the intelligent tester on.

   5. Perform the Active Test according to the display on the intelligent tester. Enter the following menus: Body Electrical / Combination Meter / Active Test.

      Combination Meter

      Tester Display	Test part	Control Range	Diagnostic Note
      Indicat. EPS	PS indicator light	PS warning light is ON/OFF	-

      OK
      P/S warning light comes on.

      Note

      If replacing the power steering ECU assembly, initialize the rotation angle sensor value and calibrate the torque sensor zero point Click here.

   
   

   NG

   REPLACE COMBINATION METER ASSEMBLY Click here

   OK

   REPLACE POWER STEERING ECU ASSEMBLY Click here