Check Bus 5 Line for Short to GND [10/2018 - 07/2022]: Procedure

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus UX 250h, 2023 Lexus UX 250h, 2022 Lexus UX 250h, 2021 Lexus UX 250h, and 2020 Lexus UX 250h. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR SHORT TO GND IN CAN BUS LINE (NO. 6 CAN JUNCTION CONNECTOR)

Disconnect the cable from the negative (-) auxiliary battery terminal.
Disconnect the No. 6 CAN junction connector.

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

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*1	DLC3	-	-
*a	Front view of wire harness connector (to No. 6 CAN Junction Connector)	*b	to No. 1 CAN Junction Connector
*c	to Air Conditioning Amplifier Assembly	*d	to Central Gateway ECU (Network Gateway ECU)
*e	to Certification ECU (Smart Key ECU Assembly)	-	-

Standard Resistance

Tester Connection	Condition	Specified Condition	Connected to
F93-1 (CANH) - F58-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	No. 1 CAN junction connector
F93-12 (CANL) - F58-4 (CG)		200 Ω or higher	No. 1 CAN junction connector
F93-2 (CANH) - F58-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Air conditioning amplifier assembly
F93-13 (CANL) - F58-4 (CG)		200 Ω or higher	Air conditioning amplifier assembly
F93-3 (CANH) - F58-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Central gateway ECU (network gateway ECU)
F93-14 (CANL) - F58-4 (CG)		200 Ω or higher	Central gateway ECU (network gateway ECU)
F93-4 (CANH) - F58-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Certification ECU (smart key ECU assembly)
F93-15 (CANL) - F58-4 (CG)		200 Ω or higher	Certification ECU (smart key ECU assembly)

Result

Result	Proceed to
OK	A
NG (Line to central gateway ECU (network gateway ECU))	B
NG (Line to No. 1 CAN junction connector)	C
NG (Line to ECU or sensor)	D

Result:

REPLACE NO. 6 CAN JUNCTION CONNECTOR

Result:

See step 3

Result:

See step 5

Result:

See step 2

CHECK FOR SHORT TO GND IN CAN BUS LINE (NO. 6 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU))

Disconnect the F61 central gateway ECU (network gateway ECU) connector.

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

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*1	DLC3	-	-
*a	Front view of wire harness connector (to No. 6 CAN Junction Connector)	*b	to Central Gateway ECU (Network Gateway ECU)

Standard Resistance

Tester Connection	Condition	Specified Condition
F93-3 (CANH) - F58-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher
F93-14 (CANL) - F58-4 (CG)		200 Ω or higher

Result

Proceed to
OK
NG

Result:

REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU). Refer to REMOVAL [10/2018 - 07/2022]

Result:

REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 6 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU))

CHECK FOR SHORT TO GND IN CAN BUS LINE (NO. 1 CAN JUNCTION CONNECTOR)

Disconnect the No. 1 CAN junction connector.

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

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*1	DLC3	-	-
*a	Front view of wire harness connector (to No. 1 CAN Junction Connector)	*b	to No. 6 CAN Junction Connector
*c	to No. 1 Headlight ECU Sub-assembly RH (w/ Automatic Headlight Beam Level Control System)	*d	to No. 1 Headlight ECU Sub-assembly LH (w/ Automatic Headlight Beam Level Control System)
*e	to Main Body ECU (Multiplex Network Body ECU)	*f	to Meter Mirror Sub-assembly (w/ Headup Display)
*g	to No. 9 CAN Junction Connector	*h	to Multiplex Tilt and Telescopic ECU (for Power Tilt and Power Telescopic Steering Column)
*i	to Outer Mirror Control ECU Assembly RH (w/ Seat Position Memory System)	-	-

Standard Resistance

Tester Connection	Condition	Specified Condition	Connected to
F85-1 (CANH) - F58-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	No. 6 CAN junction connector
F85-11 (CANL) - F58-4 (CG)		200 Ω or higher	No. 6 CAN junction connector
F85-2 (CANH) - F58-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	No. 1 Headlight ECU sub-assembly RH*4
F85-12 (CANL) - F58-4 (CG)		200 Ω or higher	No. 1 Headlight ECU sub-assembly RH*4
F85-3 (CANH) - F58-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	No. 1 Headlight ECU sub-assembly LH*4
F85-13 (CANL) - F58-4 (CG)		200 Ω or higher	No. 1 Headlight ECU sub-assembly LH*4
F85-4 (CANH) - F58-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Main body ECU (multiplex network body ECU)
F85-14 (CANL) - F58-4 (CG)		200 Ω or higher	Main body ECU (multiplex network body ECU)
F85-6 (CANH) - F58-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Meter mirror sub-assembly*1
F85-16 (CANL) - F58-4 (CG)		200 Ω or higher	Meter mirror sub-assembly*1
F85-7 (CANH) - F58-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	No. 9 CAN junction connector
F85-17 (CANL) - F58-4 (CG)		200 Ω or higher	No. 9 CAN junction connector
F85-9 (CANH) - F58-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Multiplex tilt and telescopic ECU*2
F85-19 (CANL) - F58-4 (CG)		200 Ω or higher	Multiplex tilt and telescopic ECU*2
F85-10 (CANH) - F58-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Outer mirror control ECU assembly RH*3
F85-20 (CANL) - F58-4 (CG)		200 Ω or higher	Outer mirror control ECU assembly RH*3

*1: w/ Headup Display
*2: for Power Tilt and Power Telescopic Steering Column
*3: w/ Seat Position Memory System
*4: w/ Automatic Headlight Beam Level Control System

Result

Result	Proceed to
OK	A
NG (Line to No. 6 CAN junction connector)	B
NG (Line to No. 9 CAN junction connector)	C
NG (Line to ECU or sensor)	D

Result:

REPLACE NO. 1 CAN JUNCTION CONNECTOR

Result:

REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 1 CAN JUNCTION CONNECTOR - NO. 6 CAN JUNCTION CONNECTOR)

Result:

See step 5

Result:

See step 4

CHECK FOR SHORT TO GND IN CAN BUS LINE (NO. 9 CAN JUNCTION CONNECTOR)

Disconnect the No. 9 CAN junction connector.

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

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*1	DLC3	-	-
*a	Front view of wire harness connector (to No. 9 CAN Junction Connector)	*b	to Combination Meter Assembly
*c	to Multiplex Network Door ECU (w/ Power Back Door)	*d	to No. 1 CAN Junction Connector
*e	to Position Control ECU Assembly LH (w/ Seat Position Memory System)	*f	to Outer Mirror Control ECU Assembly LH (w/ Seat Position Memory System)

Standard Resistance

Tester Connection	Condition	Specified Condition	Connected to
N112-2 (CANH) - F58-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Combination meter assembly
N112-8 (CANL) - F58-4 (CG)		200 Ω or higher	Combination meter assembly
N112-3 (CANH) - F58-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Multiplex network door ECU*1
N112-9 (CANL) - F58-4 (CG)		200 Ω or higher	Multiplex network door ECU*1
N112-4 (CANH) - F58-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	No. 1 CAN junction connector
N112-10 (CANL) - F58-4 (CG)		200 Ω or higher	No. 1 CAN junction connector
N112-5 (CANH) - F58-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Position control ECU assembly LH*2
N112-11 (CANL) - F58-4 (CG)		200 Ω or higher	Position control ECU assembly LH*2
N112-6 (CANH) - F58-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Outer mirror control ECU assembly LH*2
N112-12 (CANL) - F58-4 (CG)		200 Ω or higher	Outer mirror control ECU assembly LH*2

*1: w/ Power Back Door
*2: w/ Seat Position Memory System

Result

Result	Proceed to
OK	A
NG (Line to No. 1 CAN junction connector)	B
NG (Line to ECU or sensor)	C

Result:

REPLACE NO. 9 CAN JUNCTION CONNECTOR

Result:

REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 1 CAN JUNCTION CONNECTOR - NO. 9 CAN JUNCTION CONNECTOR)

Result:

See step 5

CHECK FOR SHORT TO GND IN CAN BUS LINE (ECU OR SENSOR)

Reconnect all wire harness connectors.
Disconnect the connector that includes terminals CANH and CANL from the ECU or sensor to which the bus line shorted to GND is connected.
Refer to TERMINALS OF ECU [10/2018 - 10/2019] , or refer to TERMINALS OF ECU [10/2019 - 08/2021] , or refer to TERMINALS OF ECU [08/2021 - 07/2022]

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

*1	DLC3	-	-
*a	Component with harness connected (Central Gateway ECU (Network Gateway ECU))	-	-

Standard Resistance

Tester Connection	Condition	Specified Condition
F61-15 (CA5H) - F58-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher
F61-16 (CA5L) - F58-4 (CG)		200 Ω or higher

HINT:

If the resistance changes to 200 Ω or higher when the connector is disconnected from the ECU or sensor, there may be a short in the ECU or sensor.
If the resistance does not become normal when the connector is disconnected from the ECU or sensor, check for a short to ground in the wire harness and repair or replace the wire harness or connector if necessary.

Result

Proceed to
OK
NG

Result:

REPLACE ECU OR SENSOR

Result:

REPAIR OR REPLACE HARNESS OR CONNECTOR