POWER ASSIST SYSTEMS  POWER STEERING SYSTEM  EPS Warning Light Circuit  


DESCRIPTION

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

WIRING DIAGRAM

C237994E12
0.99,0.542 1.396,0.698 0.406,0.156 10 false CANH 1.49,0.406 1.667,0.563 0.177,0.156 10 false 32 1.01,1.333 1.396,1.49 0.385,0.156 10 false CANL 5.938,0.542 6.344,0.698 0.406,0.156 10 false CANH 5.583,0.542 5.865,0.771 0.281,0.229 10 false E40 5.667,0.354 5.76,0.51 0.094,0.156 10 false 7 5.573,1.333 5.969,1.604 0.396,0.271 10 false E40 5.667,1.146 5.76,1.302 0.094,0.156 10 false 8 5.927,1.333 6.313,1.49 0.385,0.156 10 false CANL 5.573,2.313 5.969,2.708 0.396,0.396 10 false E40 5.656,2.135 5.75,2.292 0.094,0.156 10 false 1 5.938,2.323 6.104,2.479 0.167,0.156 10 false IG 5.573,3.125 6.052,3.51 0.479,0.385 10 false A25 5.656,2.938 5.792,3.146 0.135,0.208 10 false 2 5.927,3.135 6.354,3.292 0.427,0.156 10 false PGND 1.49,1.198 1.667,1.354 0.177,0.156 10 false 31 0.094,1.813 0.458,2.083 0.365,0.271 10 false E43 0.094,1.979 2.042,2.354 1.948,0.375 10 false Combination Meter Assembly 0.167,2.313 1.708,2.583 1.542,0.271 10 false from IG1 NO. 3 Relay 1.146,4.115 3.104,4.438 1.958,0.323 10 false : CAN Communication Line 3.25,2.458 4.219,2.833 0.969,0.375 10 false ECU-IG NO. 5 5.156,4.052 7.156,4.375 2,0.323 10 false Power Steering ECU Assembly

CAUTION / NOTICE / HINT

NOTICE:
·

If the power steering ECU assembly has been replaced, perform assist map writing and torque sensor zero point calibration.

Click hereSteering>POWER ASSIST SYSTEMS>POWER STEERING SYSTEM>CALIBRATION

·

Inspect the fuses for circuits related to this system before performing the following procedure.



PROCEDURE

1.CHECK CONNECTOR CONNECTION CONDITION
a.

Jiggle the power steering ECU assembly connectors and wire harness up and down, and left and right to check the illumination condition of the EPS warning light in the combination meter assembly.

OK:

The EPS warning light illumination condition does not change.


HINT:

When the EPS warning light is operating properly, it comes on when the ignition switch is turned to ON and goes off when the engine is started.



Result:
Proceed to
OK
NG



OK

2.CHECK CAN COMMUNICATION SYSTEM

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

2.CHECK CAN COMMUNICATION SYSTEM
a.

Check for DTCs.

Click herePower Source / Network>NETWORKING>CAN COMMUNICATION SYSTEM>DIAGNOSIS SYSTEM


Result:
Result Proceed to
CAN communication system DTCs are not output. A
CAN communication system DTCs are output. B



A

3.READ VALUE USING GTS

B

GO TO CAN COMMUNICATION SYSTEM

Click herePower Source / Network>NETWORKING>CAN COMMUNICATION SYSTEM>HOW TO PROCEED WITH TROUBLESHOOTING


3.READ VALUE USING GTS
a.

Turn the ignition switch off.


b.

Connect the GTS to the DLC3.


c.

Turn the ignition switch to ON.


d.

Turn the GTS on.


e.

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


f.

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

Chassis > EMPS > Data List
Tester Display Measurement Item Range Normal Condition Diagnostic Note
IG Power Supply IG power source voltage Min.: 0.0000 V
Max.: 20.1531 V 		8 to 16 V Ignition switch ON
Chassis > EMPS > Data List
Tester Display
IG Power Supply
50003 142 11
OK:

The normal condition value is displayed on the GTS.



Result:
Proceed to
OK
NG



OK

4.INSPECT COMBINATION METER ASSEMBLY

NG

5.CHECK HARNESS AND CONNECTOR (POWER STEERING ECU ASSEMBLY - BODY GROUND)
4.INSPECT COMBINATION METER ASSEMBLY
a.

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

Body Electrical > Combination Meter > Active Test
Tester Display
Indicat. EPS
50004 122 22

b.

Check the combination meter assembly.

OK:

The EPS warning light turns on or off in accordance with the GTS operation.



Result:
Proceed to
OK
NG



OK

REPLACE POWER STEERING ECU ASSEMBLY

Click hereSteering>POWER ASSIST SYSTEMS>POWER STEERING ECU>REMOVAL


NG

GO TO METER / GAUGE SYSTEM

Click hereVehicle Interior>METER / GAUGE / DISPLAY>METER / GAUGE SYSTEM>HOW TO PROCEED WITH TROUBLESHOOTING


5.CHECK HARNESS AND CONNECTOR (POWER STEERING ECU ASSEMBLY - BODY GROUND)
a.

Disconnect the E40 and A25 power steering ECU assembly connectors.

C268777C15
1.146,1.302 1.469,1.51 0.323,0.208 4.188,1.5 4.5,1.708 0.313,0.208 1.698,2.063 1.958,1.854 false 6.063,2.427 5.802,1.958 false 1.198,1.333 1.51,1.531 0.313,0.198 10 false E40 0.26,0.198 0.573,0.396 0.313,0.198 10 false *a 1.521,2.031 1.833,2.229 0.313,0.198 10 false IG 4.229,1.521 4.688,1.719 0.458,0.198 10 false A25 5.938,2.479 6.552,2.677 0.615,0.198 10 false PGND
*a Front view of wire harness connector
(to Power Steering ECU Assembly) 		- -



b.

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

Standard Voltage:
Tester Connection Condition Specified Condition
E40-1 (IG) - Body ground Ignition switch ON 8 to 16 V



c.

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

Standard Resistance:
Tester Connection Condition Specified Condition
A25-2 (PGND) - Body ground Always Below 1 Ω



Result:
Proceed to
OK
NG



OK

6.INSPECT COMBINATION METER ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

6.INSPECT COMBINATION METER ASSEMBLY
a.

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

Body Electrical > Combination Meter > Active Test
Tester Display
Indicat. EPS
50004 122 22

b.

Check the combination meter assembly.

OK:

The EPS warning light turns on or off in accordance with the GTS operation.



Result:
Proceed to
OK
NG



OK

REPLACE POWER STEERING ECU ASSEMBLY

Click hereSteering>POWER ASSIST SYSTEMS>POWER STEERING ECU>REMOVAL


NG

GO TO METER / GAUGE SYSTEM

Click hereVehicle Interior>METER / GAUGE / DISPLAY>METER / GAUGE SYSTEM>HOW TO PROCEED WITH TROUBLESHOOTING