Lexus RX (RX 350L, RX450h) 2016-2024 Repair Manual: LIN Communication Bus Malfunction (B2325)

DESCRIPTION

If the main body ECU (multiplex network body ECU) detects a communication error with an ECU connected to the door bus lines for 7 seconds or more, DTC B2325 will be stored.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
B2325	LIN Communication Bus Malfunction	The main body ECU (multiplex network body ECU) detects a communication error with an ECU connected to the door bus lines for 7 seconds or more.	Power window regulator motor assembly LH Power window regulator motor assembly RH Power window regulator motor assembly (for rear RH door) Power window regulator motor assembly (for rear LH door) Multiplex network master switch assembly Sliding roof ECU (sliding roof drive gear sub-assembly)*1*2 Roof sunshade ECU (sliding roof drive gear sub-assembly)*2 Kick door control sensor*3 Main body ECU (multiplex network body ECU) Instrument panel junction block assembly Wire harness or connector ECU-B NO. 2 fuse DOOR F/L fuse DOOR F/R fuse DOOR R/L fuse DOOR R/R fuse S/ROOF fuse*1*2 S/ROOF NO. 2 fuse *2 ECU-DCC NO. 2 fuse*3

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1.	INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Remove the instrument panel junction block assembly.

Click here

*a

Component without harness connected (Instrument Panel Junction Block Assembly)

-

-

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

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

HINT:

This inspection is to check the LIN communication line in the instrument panel junction block assembly that connects the wire harness to the built-in main body ECU (multiplex network body ECU).

Standard Resistance:

Tester Connection	Condition	Specified Condition
2D-25 - MB-16 (LIN2)	Always	Below 1 Ω
2B-17 - MB-16 (LIN2)	Always	Below 1 Ω

NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

OK

2.	CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - EACH ECU)

(a) Disconnect the N13 power window regulator motor assembly LH connector.

(b) Disconnect the M13 power window regulator motor assembly RH connector.

(c) Disconnect the P1 power window regulator motor assembly (for rear LH door) connector.

(d) Disconnect the O1 power window regulator motor assembly (for rear RH door) connector.

(e) Disconnect the N7 multiplex network master switch assembly connector.

(f) Disconnect the U2 sliding roof ECU (sliding roof drive gear sub-assembly) connector.*1

(g) Disconnect the U2 sliding roof ECU (sliding roof drive gear assembly) connector.*2

(h) Disconnect the w1 roof sunshade ECU (sliding roof drive gear assembly) connector.*2

(i) Disconnect the Y9 kick door control sensor connector.*3

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

NOTICE:

Make sure that each ECU is in sleep mode before performing the inspection. To enter sleep mode, turn the engine switch from on (IG) to off and wait for 180 seconds or more without operating any switches.

Standard Resistance:

Tester Connection	Condition	Specified Condition
3H-25 - N7-17 (LIN1)	Engine switch off	Below 1 Ω
3D-17 - U2-7 (MPX1)*1*2	Engine switch off	Below 1 Ω
3D-17 - w1-7 (MPX1)*2	Engine switch off	Below 1 Ω
2B-17 - Y9-2 (LIN)*3	Engine switch off	Below 1 Ω
3H-25 - M13-9 (LIN)	Engine switch off	Below 1 Ω
3H-25 - P1-9 (LIN)	Engine switch off	Below 1 Ω
3H-25 - O1-9 (LIN)	Engine switch off	Below 1 Ω
3H-25 - N13-9 (LIN)	Engine switch off	Below 1 Ω
N7-17 (LIN1) - Body ground	Engine switch off	10 kΩ or higher
U2-7 (MPX1) - Body ground*1*2	Engine switch off	10 kΩ or higher
w1-7 (LIN) - Body ground*2	Engine switch off	10 kΩ or higher
Y9-2 (LIN) - Body ground*3	Engine switch off	10 kΩ or higher
3H-25 or 3D-17 - Body ground	Engine switch off	10 kΩ or higher
M13-9 (LIN) - Body ground	Engine switch off	10 kΩ or higher
P1-9 (LIN) - Body ground	Engine switch off	10 kΩ or higher
O1-9 (LIN) - Body ground	Engine switch off	10 kΩ or higher
N13-9 (LIN) - Body ground	Engine switch off	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.	CHECK POWER WINDOW REGULATOR MOTOR ASSEMBLY (for Rear LH Door)

(a) Reconnect the 2B and 2D instrument panel junction block assembly connectors.

(b) Reconnect the N13 power window regulator motor assembly LH connector.

(c) Reconnect the M13 power window regulator motor assembly RH connector.

(d) Reconnect the O1 power window regulator motor assembly (for rear RH door) connector.

(e) Reconnect the N7 multiplex network master switch assembly connector.

(f) Reconnect the U2 sliding roof ECU (sliding roof drive gear sub-assembly) connector.*1

(g) Reconnect the U2 sliding roof ECU (sliding roof drive gear assembly) connector.*2

(h) Reconnect the w1 roof sunshade ECU (sliding roof drive gear assembly) connector.*2

(i) Reconnect the Y9 kick door control sensor connector.*3

(j) Clear the DTCs.

Click here

Body Electrical > Main Body > Clear DTCs

(k) After 10 seconds have elapsed, check if the same DTC is output again.

Body Electrical > Main Body > Trouble Codes

Result	Proceed to
DTC B2325 is output	A
DTC B2325 is not output	B

B

REPLACE POWER WINDOW REGULATOR MOTOR ASSEMBLY (for Rear LH Door)

A

4.	CHECK MULTIPLEX NETWORK MASTER SWITCH ASSEMBLY

(a) Reconnect the P1 power window regulator motor assembly (for rear LH door) connector.

(b) Disconnect the N7 multiplex network master switch assembly connector.

(c) Clear the DTCs.

Click here

Body Electrical > Main Body > Clear DTCs

(d) After 10 seconds have elapsed, check if the same DTC is output again.

Body Electrical > Main Body > Trouble Codes

Result	Proceed to
DTC B2325 is output	A
DTC B2325 is not output	B

B

REPLACE MULTIPLEX NETWORK MASTER SWITCH ASSEMBLY

A

5.	CHECK POWER WINDOW REGULATOR MOTOR ASSEMBLY (for Rear RH Door)

(a) Reconnect the N7 multiplex network master switch assembly connector.

(b) Disconnect the O1 power window regulator motor assembly (for rear RH door) connector.

(c) Clear the DTCs.

Click here

Body Electrical > Main Body > Clear DTCs

(d) After 10 seconds have elapsed, check if the same DTC is output again.

Body Electrical > Main Body > Trouble Codes

Result	Proceed to
DTC B2325 is output	A
DTC B2325 is not output	B

B

REPLACE POWER WINDOW REGULATOR MOTOR ASSEMBLY (for Rear RH Door)

A

6.	CHECK POWER WINDOW REGULATOR MOTOR ASSEMBLY LH

(a) Reconnect the O1 power window regulator motor assembly (for rear RH door) connector.

(b) Disconnect the N13 power window regulator motor assembly LH connector.

(c) Clear the DTCs.

Click here

Body Electrical > Main Body > Clear DTCs

(d) After 10 seconds have elapsed, check if the same DTC is output again.

Body Electrical > Main Body > Trouble Codes

Result	Proceed to
DTC B2325 is output	A
DTC B2325 is not output	B

B

REPLACE POWER WINDOW REGULATOR MOTOR ASSEMBLY LH

A

7.	CHECK POWER WINDOW REGULATOR MOTOR ASSEMBLY RH

(a) Reconnect the N13 power window regulator motor assembly LH connector.

(b) Disconnect the M13 power window regulator motor assembly RH connector.

(c) Clear the DTCs.

Click here

Body Electrical > Main Body > Clear DTCs

(d) After 10 seconds have elapsed, check if the same DTC is output again.

Body Electrical > Main Body > Trouble Codes

Result	Proceed to
DTC B2325 is output	A
DTC B2325 is not output	B

B

REPLACE POWER WINDOW REGULATOR MOTOR ASSEMBLY RH

A

8.	SYSTEM CHECK

(a) Check the vehicle specification.

Proceed to	Proceed to
w/ Sliding Roof System	A
w/ Panoramic Moon Roof System	B
w/o Sliding Roof System or Panoramic Moon Roof System	C

B

GO TO STEP 12

C

GO TO STEP 10

A

9.	CHECK SLIDING ROOF ECU (SLIDING ROOF DRIVE GEAR SUB-ASSEMBLY)

(a) Reconnect each ECU connector.

(b) Disconnect the U2 sliding roof ECU (sliding roof drive gear sub-assembly) connector.

(c) Clear the DTCs.

Click here

Body Electrical > Main Body > Clear DTCs

(d) After 10 seconds have elapsed, check if the same DTC is output again.

Body Electrical > Main Body > Trouble Codes

Result	Proceed to
DTC B2325 is output	A
DTC B2325 is not output	B

B

REPLACE SLIDING ROOF ECU (SLIDING ROOF DRIVE GEAR SUB-ASSEMBLY)

A

10.	SYSTEM CHECK

(a) Check the vehicle specification.

Proceed to	Proceed to
w/ Hands Free Power Back Door	A
w/o Hands Free Power Back Door	B

B

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

A

11.	CHECK KICK DOOR CONTROL SENSOR

(a) Reconnect each ECU connector.

(b) Disconnect the Y9 kick door control sensor connector.

(c) Clear the DTCs.

Click here

Body Electrical > Main Body > Clear DTCs

(d) After 10 seconds have elapsed, check if the same DTC is output again.

Body Electrical > Main Body > Trouble Codes

Result	Proceed to
DTC B2325 is output	A
DTC B2325 is not output	B

A

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

B

REPLACE KICK DOOR CONTROL SENSOR

12.	CHECK ROOF SUNSHADE ECU (SLIDING ROOF DRIVE GEAR ASSEMBLY)

(a) Reconnect each ECU connector.

(b) Disconnect the w1 roof sunshade ECU (sliding roof drive gear assembly) connector.

(c) Clear the DTCs.

Click here

Body Electrical > Main Body > Clear DTCs

(d) After 10 seconds have elapsed, check if the same DTC is output again.

Body Electrical > Main Body > Trouble Codes

Result	Proceed to
DTC B2325 is output	A
DTC B2325 is not output	B

B

REPLACE ROOF SUNSHADE ECU (SLIDING ROOF DRIVE GEAR ASSEMBLY)

A

13.	CHECK SLIDING ROOF ECU (SLIDING ROOF DRIVE GEAR ASSEMBLY)

(a) Reconnect each ECU connector.

(b) Disconnect the U2 sliding roof ECU (sliding roof drive gear assembly) connector.

(c) Clear the DTCs.

Click here

Body Electrical > Main Body > Clear DTCs

(d) After 10 seconds have elapsed, check if the same DTC is output again.

Body Electrical > Main Body > Trouble Codes

Result	Proceed to
DTC B2325 is output	A
DTC B2325 is not output	B

A

GO TO STEP 10

B

REPLACE SLIDING ROOF ECU (SLIDING ROOF DRIVE GEAR ASSEMBLY)