Main Body ECU Communication Stop Mode [10/2018 - 07/2022]: Procedure

1. Disconnect the cable from the negative (-) auxiliary battery terminal.
2. Disconnect the main body ECU (multiplex network body ECU) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F40-5 (CANH) - F40-4 (CANL)	Cable disconnected from negative (-) auxiliary battery terminal	54 to 69 Ω

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE CAN BRANCH LINES OR CONNECTOR (MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)) 

Result: 

OK 

See step  2

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

   Refer to REMOVAL [10/2018 - 07/2022]

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   MB-11 (GND1) - Body ground	Cable disconnected from negative (-) auxiliary battery terminal	Below 1 Ω

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   NOTE:

   Perform this inspection with the wire harness connected to the instrument panel junction block assembly.

3. Reconnect the cable to the negative (-) auxiliary battery terminal.
4. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   MB-30 (ACC) - Body ground	Engine switch on (ACC)	11 to 14 V
   MB-31 (BECU) - Body ground	Always	11 to 14 V
   MB-32 (IG) - Body ground	Engine switch on (IG)	11 to 14 V

   NOTE:

   Perform this inspection with the wire harness connected to the instrument panel junction block assembly.

   Result

   Result	Proceed to
   OK	A
   NG (BECU)	B
   NG (ACC)	C
   NG (IG)	D
   NG (GND1)	E

Result: 

A 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [10/2018 - 07/2022] 

Result: 

C 

GO TO LIGHTING (INT) SYSTEM (ACC SIGNAL CIRCUIT). Refer to  ACC Signal Circuit [10/2018 - 07/2022] 

Result: 

D 

GO TO LIGHTING (INT) SYSTEM (IG SIGNAL CIRCUIT). Refer to  IG Signal Circuit [10/2018 - 07/2022] 

Result: 

E 

See step  4

Result: 

B 

See step  3

1. Disconnect the cable from the negative (-) auxiliary battery terminal.
2. Disconnect the instrument panel junction block assembly connector.
3. Reconnect the cable to the negative (-) auxiliary battery terminal.
4. 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	Condition	Specified Condition
   4B-23 - Body ground	Always	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY. Refer to  REMOVAL [10/2018 - 07/2022] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (BECU SIGNAL CIRCUIT) 

1. Disconnect the cable from the negative (-) auxiliary battery terminal.
2. Disconnect the instrument panel junction block assembly connector.
3. Measure the resistance 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 Resistance

   Tester Connection	Condition	Specified Condition
   4B-3 - Body ground	Cable disconnected from negative (-) auxiliary battery terminal	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY. Refer to  REMOVAL [10/2018 - 07/2022] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (GROUND CIRCUIT)