POWER STEERING SYSTEM EPS Warning Light Circuit

DESCRIPTION

If the power steering ECU detects a malfunction, the P/S warning light comes on. At this time, the power steering ECU stores a DTC in its memory.

INSPECTION PROCEDURE

PROCEDURE

1. Click here

   CHECK FOR DTC (CAN COMMUNICATION SYSTEM)

   
   

   1. Turn the ignition switch off.

   2. Connect the intelligent tester to the DLC3.

   3. Turn the ignition switch on (IG).

   4. Turn the intelligent tester on.

   5. Using the intelligent tester, check for DTCs and confirm that there are no problems in the CAN communication system.

      OK
      CAN DTCs are not output.

   
   
   • OKClick here
   • NGClick here
2. Click here

   READ VALUE USING INTELLIGENT TESTER (IG POWER SUPPLY)

   
   

   1. Enter the following menus: Chassis / EMPS / Data List.

   2. Select the item "IG Power Supply" in the Data List and read the value displayed on the intelligent tester.

      Table 1. EMPS:

      Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
      IG Power Supply	ECU power source voltage: Min.: 0 V Max.: 20.1531 V	11 to 14 V	Ignition switch on (IG)

   
   
   • OKClick here
   • NGClick here
3. Click here

   PERFORM ACTIVE TEST BY INTELLIGENT TESTER

   
   

   1. Enter the following menus: Body / Combination meter / Active Test.

   2. According to the display on tester, perform the "Active Test".

      Table 2. Combination meter:

      Tester Display	Test Part	Control Range	Diagnostic Note
      Indicat. EPS (*1)	P/S Warning Light	ON or OFF	Confirm that the vehicle is stopped, engine idling
      Master Warning (*2)	Master Warning Light	ON or OFF	Confirm that the vehicle is stopped, engine idling

      *1: w/o Multi-information Display

      *2: w/ Multi-information Display

      OK
      Indicator comes on.

   
   
   • OKClick here
   • NGClick here
4. Click here

   INSPECT FUSE (ECU IG NO. 1)

   
   

   1. Remove the ECU IG No. 1 fuse from the instrument panel junction block.

   2. Measure the resistance of the fuse.

      OK
      Below 1 Ω

   
   
   • OKClick here
   • NGClick here
5. Click here

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

   
   
   1. 

      Disconnect the connectors from the power steering ECU.

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

      Standard voltage
      Tester Connection Switch Condition Specified Condition D5-5 (IG) - Body ground Ignition switch on (IG) 11 to 14 V

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

      Standard resistance
      Tester Connection Condition Specified Condition D4-2 (PGND) - Body ground Always Below 1 Ω

   
   
   • OKClick here
   • NGClick here
6. Click here

   PERFORM ACTIVE TEST USING INTELLIGENT TESTER

   
   

   1. Enter the following menus: Body / Combination meter / Active Test.

   2. According to the display on the tester, perform the "Active Test".

      Table 3. Combination meter:

      Tester Display	Test Part	Control Range	Diagnostic Note
      Indicat. EPS (*1)	P/S Warning Light	ON or OFF	Confirm that the vehicle is stopped, engine idling
      Master Warning (*2)	Master Warning Light	ON or OFF	Confirm that the vehicle is stopped, engine idling

      *1: w/o Multi-information Display

      *2: w/ Multi-information Display

      OK
      Indicator comes on.

   
   
   • OKClick here
   • NGClick here
7. Click here

   GO TO CAN COMMUNICATION SYSTEMClick here

8. Click here

   REPLACE COMBINATION METER ASSEMBLYClick here

9. Click here

   REPLACE POWER STEERING ECUClick here

10. Click here

    REPLACE FUSE

11. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR