EPS Warning Light Circuit: Procedure

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

   OK

   The electric power steering column sub-assembly and power steering ECU assembly connectors are securely connected.

2. Check that the ground wire is securely installed with the bolt. Refer to INSTALLATION - Step 3 .

   OK

   The ground wire is securely installed with the bolt.

NG → See step   11 

OK: Go to next step 

1. Check for DTCs. Refer to DIAGNOSIS SYSTEM .

   OK

   DTC is not output.

NG → See step   10 

OK: Go to next step 

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.
   EMPS
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   IG power supply	IG power supply/ Min.: 0.0000 V Max.: 20.1531 V	9 to 16 V	Ignition switch ON

   OK

   The normal condition value is displayed on the Techstream.

NG → See step   4 

OK → See step   9 

1. Disconnect the Ij2 connector from the ECU wire sub-assembly.
   Fig 1: Checking Wire Harness And Connector (Battery - ECU Wire Sub-Assembly)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   Ij2-5 (IG) - Body ground	Ignition switch ON	9 to 16 V

   TEXT IN ILLUSTRATION
   
   

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

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the j2 connector from the power steering ECU assembly.
   Fig 2: Checking Harness And Connector (Power Steering ECU Assembly - Body Ground)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   j2-2 (PGND) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

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

NG → See step   13 

OK: Go to next step 

1. Disconnect the j1 connector from the power steering ECU assembly.
   Fig 3: Checking Resistance Of ECU Wire Sub-Assembly

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   j1-1 (IG) - Ij2-5 (IG)	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Power Steering ECU Assembly)
   *b	Front view of wire harness connector (to Vehicle Wire Harness)

NG → See step   13 

OK: Go to next step 

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: Body Electrical / Combination Meter / Active Test.
6. Perform the Active Test of the combination meter assembly using the Techstream.
   COMBINATION METER
   
   

   Tester Display	Test Part	Control Range	Diagnostic Note
   Indicat. EPS	EPS warning light	OFF or ON	Confirm that the vehicle is stopped with the engine idling

7. Check that the EPS warning light operates in accordance with the Active Test.

   HINT: 

   Reconnect the connectors and restore the vehicle to its previous condition before checking the combination meter assembly.

NG → See step   8 

OK → See step   12