EPS Warning Light Circuit [08/2013 - 08/2016]: Procedure

1. 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

Result:  2

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result:  1

OK 

See step  2

1. Check for DTCs.

   Refer to DIAGNOSIS SYSTEM [08/2013 - 04/2014] Refer to DIAGNOSIS SYSTEM [04/2014 - 08/2015] Refer to DIAGNOSIS SYSTEM [08/2015 - 08/2016]

   Result

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

Result:  2

B 

GO TO CAN COMMUNICATION SYSTEM:  HOW TO PROCEED WITH TROUBLESHOOTING [08/2013 - ] 

Result:  1

A 

See step  3

1. Turn the ignition switch off.
2. Connect the Techstream to the DLC3.
3. Turn the ignition switch to ON.
4. Turn the Techstream on.
5. Enter the following menus: Chassis / EMPS / Data List.
6. Select the item "IG Power Supply" in the Data List and read the value displayed on the Techstream.

   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

   OK

   The normal condition value is displayed on the Techstream.

   Result

   Proceed to
   OK
   NG

Result:  2

NG 

See step  5

Result:  1

OK 

See step  4

1. Perform the Active Test of the combination meter assembly using the Techstream.

   Body Electrical > Combination Meter > Active Test 

   Tester Display
   Indicat. EPS

2. Check the combination meter assembly.

   OK

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

   Result

   Proceed to
   OK
   NG

Result:  1

OK 

REPLACE POWER STEERING ECU ASSEMBLY. Refer to  REMOVAL [08/2013 - ] 

Result:  2

NG 

GO TO METER / GAUGE SYSTEM:  HOW TO PROCEED WITH TROUBLESHOOTING [08/2013 - 08/2016] 

1. Disconnect the E40 and A25 power steering ECU assembly connectors.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a

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

   -

   -

2. 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

3. 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

Result:  2

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result:  1

OK 

See step  6

1. Perform the Active Test of the combination meter assembly using the Techstream.

   Body Electrical > Combination Meter > Active Test 

   Tester Display
   Indicat. EPS

2. Check the combination meter assembly.

   OK

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

   Result

   Proceed to
   OK
   NG

Result:  1

OK 

REPLACE POWER STEERING ECU ASSEMBLY. Refer to  REMOVAL [08/2013 - ] 

Result:  2

NG 

GO TO METER / GAUGE SYSTEM:  HOW TO PROCEED WITH TROUBLESHOOTING [08/2013 - 08/2016]