POWER STEERING SYSTEM Power Steering Warning Light Circuit

DESCRIPTION

The power steering ECU is connected to the combination meter via CAN communication. If any of the following conditions are detected, the power steering warning light remains on.

• The circuit that supplies power source voltage to the power steering ECU assembly (terminal IG) is open.

• The power supply voltage to the power steering ECU assembly (terminals IG and PIG) drops.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. CHECK CONNECTOR CONNECTION CONDITION AND GROUND WIRE

   
   

   1. Check the connection condition of the ECU wire sub-assembly and power steering ECU assembly connectors.

      OK
      The ECU wire sub-assembly and power steering ECU assembly connectors are securely connected.

   2. Check that the ground wire is securely installed with the bolt.

      Click here

      OK
      The ground wire is securely installed with the bolt.

      Result
      Proceed to OK NG

   
   

   NG

   CONNECT CONNECTOR OR INSTALL GROUND WIRE Click here

   OK

2. CHECK FOR DTC (CAN COMMUNICATION SYSTEM)

   
   

   1. Check for DTCs.

      Click here

      
      Chassis > EMPS > Trouble Codes

      OK
      DTC is not output.

      Result
      Proceed to OK NG

   
   

   NG

   GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) for LHD with Central Gateway ECU: Click here GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) for RHD with Central Gateway ECU: Click here GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) for LHD without Central Gateway ECU: Click here GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) for RHD without Central Gateway ECU: Click here

   OK

3. CHECK HARNESS AND CONNECTOR (IG POWER SUPPLY)

   
   
   1. 

      *a	Front view of wire harness connector (to ECU Wire Sub-assembly)

      Disconnect the hG1 ECU wire sub-assembly connector.

   2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition hG1-5 (IG) - Body ground Ignition switch ON 11 to 14 V

      Result
      Proceed to OK NG (w/o Stop and Start System) NG (w/ Stop and Start System)

   
   

   NG (w/o Stop and Start System)

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   NG (w/ Stop and Start System)

   GO TO STOP AND START SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) for 2WW: Click here GO TO STOP AND START SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) for 3ZR-FAE: Click here

   OK

4. CHECK ECU WIRE SUB-ASSEMBLY

   
   
   1. 

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

      Connect the hG1 connector to the ECU wire sub-assembly.

   2. Disconnect the h1 and h2 power steering ECU assembly connectors.

   3. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition h1-1 (IG) - Body ground Ignition switch ON 11 to 14 V

   5. Turn the ignition switch off.

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

      Standard Resistance
      Tester Connection Condition Specified Condition h2-2 (PGND) - Body ground Always Below 1 Ω

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE ECU WIRE SUB-ASSEMBLY Click here

   OK

5. CHECK HARNESS AND CONNECTOR (BATTERY - ECU WIRE SUB-ASSEMBLY)

   
   
   1. 

      *a	Front view of wire harness connector (to ECU Wire Sub-assembly)

      Disconnect the Ah1 ECU wire sub-assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition Ah1-1 (PIG) - Body ground Always 11 to 14 V

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

6. CHECK ECU WIRE SUB-ASSEMBLY

   
   
   1. 

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

      Connect the Ah1 connector to the ECU wire sub-assembly.

   2. Disconnect the h2 power steering ECU assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition h2-1 (PIG) - Body ground Always 11 to 14 V

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE ECU WIRE SUB-ASSEMBLY Click here

   OK

7. INSPECT COMBINATION METER ASSEMBLY

   
   

   1. Reconnect the h1 and h2 power steering ECU assembly connectors.

   2. Perform the Active Test of the combination meter assembly using the GTS.

      Click here

      
      Body Electrical > Combination Meter > Active Test

      Tester Display
      Indicat. EPS

   3. Check the combination meter assembly.

      OK
      The power steering warning light turns on or off in accordance with the GTS operation.

      Result
      Proceed to OK NG

   
   

   OK

   REPLACE POWER STEERING ECU ASSEMBLY Click here

   NG

   REPLACE COMBINATION METER ASSEMBLY Click here