Main Body ECU Communication Stop Mode [11/2018 - 02/2019]: Procedure

1. Disconnect the cable from the negative (-) auxiliary battery terminal.
2. Disconnect the main body ECU (multiplex network body ECU) connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Main Body ECU [Multiplex Network Body ECU])

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G44-5 (CANH) - G44-4 (CANL)	Cable disconnected from negative (-) auxiliary battery terminal	54 to 69 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR 

Result: 

OK 

See step  2

1. Remove the main body ECU (multiplex network body ECU).

   Refer to REMOVAL [11/2018 - 02/2019]

2. Connect 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
   A-11 (GND1) - Body ground	Cable disconnected from negative (-) auxiliary battery terminal	Below 1 Ω

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component without harness connected (Instrument Panel Junction Block Assembly)

4. Reconnect the cable to the negative (-) auxiliary battery terminal.
   NOTE:

   When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

   Refer to INITIALIZATION [11/2018 - 02/2019]

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

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A-31 (BECU) - Body ground	Power switch off	11 to 14 V
   A-30 (ACC) - Body ground	Power switch on (ACC)	11 to 14 V
   	Power switch off	Below 1 V
   A-32 (IG) - Body ground	Power switch on (IG)	11 to 14 V
   	Power switch off	Below 1 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU] 

Refer to REMOVAL [11/2018 - 02/2019]

Result: 

NG 

See step  3

1. Disconnect the instrument panel junction block assembly connectors.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a

   Front view of wire harness connector (to Instrument Panel Junction Block Assembly)

   -

   -

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   4D-3 - Body ground	Always	Below 1 Ω

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

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   4K-1 - Body ground	Power switch off	11 to 14 V
   4D-23 - Body ground	Power switch off	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

1. Disconnect the instrument panel junction block assembly connector.
2. Measure the voltage according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Instrument Panel Junction Block Assembly)

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   4A-30 - Body ground	Power switch on (ACC)	11 to 14 V
   	Power switch off	Below 1 V
   4A-17 - Body ground	Power switch on (IG)	11 to 14 V
   	Power switch off	Below 1 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 

Refer to REMOVAL [11/2018 - 02/2019]

Result: 

NG 

GO TO SMART KEY SYSTEM (for Start Function) 

Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2018 - 02/2019]