IG Signal Circuit [03/2017 - ]: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Body Electrical / Main Body / Data List.
5. Read the Data List according to the display on the Techstream.

   Body Electrical > Main Body > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   IG SW	Ignition switch ON signal	OFF or ON	OFF: Ignition switch off ON: Ignition switch ON	"OFF" is also displayed for this item when the ignition switch is ACC.

   Body Electrical > Main Body > Data List 

   Tester Display
   IG SW

   OK

   Normal conditions listed above are displayed.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [03/2017 - 06/2017]  , or refer to  PROBLEM SYMPTOMS TABLE [06/2017 - 09/2019]  , or refer to  PROBLEM SYMPTOMS TABLE [09/2019 - 08/2021]  , or refer to  PROBLEM SYMPTOMS TABLE [08/2021 - ] 

Result: 

NG 

See step  2

1. Disconnect the 3F instrument panel junction block assembly connector.
2. Disconnect the 3B instrument panel junction block assembly connector.
3. Disconnect the K51 main body ECU (multiplex network body ECU) connector.
4. Measure the voltage and resistance according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   3F-1 - Body ground	Always	11 to 14 V

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3B-3 - Body ground	Always	Below 1 Ω
   K51-19 (GND2) - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  3

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the instrument panel junction block assembly.

   Refer to REMOVAL [03/2017 - 06/2017] , or refer to REMOVAL [06/2017 - 10/2020] , or refer to REMOVAL [10/2020 - ]

2. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

   Refer to REMOVAL [03/2017 - 06/2017] , or refer to REMOVAL [06/2017 - 10/2020] , or refer to REMOVAL [10/2020 - ]

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3F-1 - MB-32 (IG)	Battery not connected to 3A-17 and 3B-3	10 kΩ or higher
   3F-1 - MB-32 (IG)	Battery positive (+) → 3A-17 Battery negative (-) → 3B-3	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [03/2017 - 06/2017]  , or refer to  REMOVAL [06/2017 - 10/2020]  , or refer to  REMOVAL [10/2020 - ] 

Result: 

NG 

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY. Refer to  REMOVAL [03/2017 - 06/2017]  , or refer to  REMOVAL [06/2017 - 10/2020]  , or refer to  REMOVAL [10/2020 - ]