Power Source Mode does not Change to ON (IG) [11/2018 - ]: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Body Electrical / Smart Key, Power Source Control / Trouble Codes.
5. Check for DTCs.

   Body Electrical > Smart Key > Trouble Codes 

   Body Electrical > Power Source Control > Trouble Codes 

   Result

   Result	Proceed to
   DTCs are not output	A
   Smart key system (for Start Function) DTCs are output	B

Result: 

B 

GO TO DIAGNOSTIC TROUBLE CODE CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [11/2018 - 02/2019]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [02/2019 - ] 

Result: 

A 

See step  2

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component with harness connected (Certification ECU (Smart Key ECU Assembly))

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   G54-17 (IG1D) - Body ground	Power switch on (ACC) → Power switch on (IG)	1 V or less → 9 V or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [11/2018 - 02/2019]  , or refer to  REMOVAL [02/2019 - 10/2019]  , or refer to  REMOVAL [10/2019 - 08/2020]  , or refer to  REMOVAL [08/2020 - 12/2021]  , or refer to  REMOVAL [12/2021 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023]  , or refer to  REMOVAL [10/2023 - ] 

Result: 

OK 

See step  3

1. Disconnect the G54 certification ECU (smart key ECU assembly) connector.
2. Disconnect the 4A, 4D and 4L instrument panel junction block assembly connectors.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G54-17 (IG1D) - 4A-30	Always	Below 1 Ω
   4D-3 - Body ground	Always	Below 1 Ω
   G54-17 (IG1D) or 4A-30 - Other terminals and body ground	Always	10 kΩ or higher

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   4A-17 - Body ground	Always	11 to 14 V
   4L-1 - Body ground	Always	11 to 14 V

5. Reconnect the G54 certification ECU (smart key ECU assembly) connector.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the instrument panel junction block assembly.

   Refer to REMOVAL [11/2018 - 02/2019] , or refer to REMOVAL [02/2019 - 10/2019] , or refer to REMOVAL [10/2019 - 08/2020] , or refer to REMOVAL [08/2020 - 12/2021] , or refer to REMOVAL [12/2021 - 10/2022] , or refer to REMOVAL [10/2022 - 10/2023] , or refer to REMOVAL [10/2023 - ]

2. Reconnect the instrument panel junction block assembly connectors.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   4A-17 - 4F-13	Always	Below 1 Ω

4. Connect a positive (+) lead from the auxiliary battery to terminal 4A-17.
5. Connect a negative (-) lead from the auxiliary battery to terminal 4D-3.
6. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   4K-1 - 4D-31	Always	Below 1 Ω
   4K-1 - 4F-2	Always	Below 1 Ω
   4L-1 - 4F-15	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY. Refer to  REMOVAL [11/2018 - 02/2019]  , or refer to  REMOVAL [02/2019 - 10/2019]  , or refer to  REMOVAL [10/2019 - 08/2020]  , or refer to  REMOVAL [08/2020 - 12/2021]  , or refer to  REMOVAL [12/2021 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023]  , or refer to  REMOVAL [10/2023 - ] 

Result: 

OK 

See step  5

1. Disconnect the 4F instrument panel junction block assembly connector.
2. Remove the IG2 NO. 1 relay.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   4F-13 - IG2 NO. 1 relay installation terminal 1	Always	Below 1 Ω
   IG2 NO. 1 relay installation terminal 2 - Body ground	Always	Below 1 Ω
   4F-13 or IG2 NO. 1 relay installation terminal 1 - Other terminals and body ground	Always	10 kΩ or higher

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   IG2 NO. 1 relay installation terminal 5 - Body ground	Always	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  6

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3 - 5	Auxiliary battery voltage applied between terminals 1 and 2	Below 1 Ω
   	Auxiliary battery voltage not applied between terminals 1 and 2	10 kΩ or higher

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *1	IG2 NO. 1 Relay

   Result

   Proceed to
   OK
   NG

Result: 

OK 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [11/2018 - ] 

Result: 

NG 

REPLACE IG2 NO. 1 RELAY