EPS Warning Light Circuit [11/2023 - ]: Procedure

1. Check the vehicle control history (RoB).

   Refer to VEHICLE CONTROL HISTORY (RoB) [11/2023 - ] 

   HINT: 

   If vehicle control history (RoB) is stored, the EPS warning light may illuminate.

   Result

   Result	Proceed to
   Vehicle control history (RoB) of power steering system control does not exist	A
   Vehicle control history (RoB) of power steering system control exists	B

Result: 

B 

PERFORM INSPECTIONS AND REPAIRS ON THE SYSTEM RELATED TO THE VEHICLE CONTROL HISTORY (RoB) 

Refer to VEHICLE CONTROL HISTORY (RoB) [11/2023 - ] 

Result: 

A 

See step  2

1. Jiggle the rack and pinion power steering gear 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: 

   for HV Model: 

   1. When the EPS warning light is operating properly, it illuminates when the ignition switch is turned to ON and turns off when the ignition switch is ON (READY).

   for Gasoline Model: 

   1. When the EPS warning light is operating properly, it illuminates when the ignition switch is turned to ON and turns off when the engine is started.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  3

1. Disconnect the C67 rack and pinion power steering gear assembly connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a

   Front view of wire harness connector (to Rack and Pinion Power Steering Gear Assembly)

   -

   -

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   C67-4 (IG) - Body ground	Ignition switch ON	11 to 14 V*1 10.5 to 16 V*2

   *1: w/o Stop and Start System

   *2: w/ Stop and Start System

   Result

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

Result: 

B 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

C 

GO TO STOP AND START SYSTEM (BACKUP BOOST CONVERTER CIRCUIT). Refer to  Backup Boost Converter Circuit [11/2023 - ] 

Result: 

A 

See step  4

1. Turn the ignition switch off.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a

   Front view of wire harness connector (to Rack and Pinion Power Steering Gear Assembly)

   -

   -

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   C67-8 (PIG) - Body ground	Ignition switch off	11 to 14 V

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   C67-7 (PGND) - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  5

1. Check the vehicle specification.

   Result

   Result	Proceed to
   Combination Meter Assembly (except 12.3 Inch Display)	A
   Combination Meter Assembly (for 12.3 Inch Display)	B

Result: 

B 

See step  7

Result: 

A 

See step  6

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

   Refer to DATA LIST / ACTIVE TEST [11/2023 - ]

   Body Electrical > Combination Meter > Active Test 

   Tester Display
   EPS Warning

2. 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

Result: 

OK 

REPLACE RACK AND PINION POWER STEERING GEAR ASSEMBLY. Refer to  REMOVAL [11/2023 - ] 

Result: 

NG 

GO TO METER / GAUGE SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - ] 

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

   Refer to DATA LIST / ACTIVE TEST [11/2023 - ]

   Body Electrical > Combination Meter > Active Test 

   Tester Display
   Multi Display All (White)

2. Check the combination meter assembly.

   OK

   The multi-information display in the combination meter assembly turns on according to the operation of the Active Test.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE RACK AND PINION POWER STEERING GEAR ASSEMBLY. Refer to  REMOVAL [11/2023 - ] 

Result: 

NG 

GO TO METER / GAUGE SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2022 - ]