Toyota Venza: Back Door Closer Switch Malfunction (B2251)

Toyota Venza Service Manual / Door / Hatch / Back Door Closer System / Back Door Closer Switch Malfunction (B2251)

DESCRIPTION

The power back door ECU (power back door motor unit)*1 or back door closer ECU (multiplex network door ECU)*2 receives signals from the latch switch, sector switch and back door courtesy switch, which are built into the back door lock. Based on these switch signals, the latch position of the back door lock is determined.

DTC No.	DTC Detection Condition	Trouble Area
B2251	While the back door closer is operating, a malfunction is detected in position information from the back door courtesy switch within a specified amount of time.	Back door lock assembly Wire harness or connector Power back door ECU (Power back door motor unit)1 Back door closer ECU (Multiplex network door ECU)2

*1: w/ Power Back Door System
*2: w/o Power Back Door System

WIRING DIAGRAM

PROCEDURE

1.	READ VALUE USING TECHSTREAM (BACK DOOR COURTESY SWITCH)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Enter the following menus: Body Electrical / Back Door / Data List.

(e) Check if the switch functions properly.

Back Door (Power Back Door ECU*1 or Back Door Closer ECU*2)

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Courtesy SW	Back door courtesy switch signal / ON or OFF	ON: Back door open OFF: Back door closed	-

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Courtesy SW

Back door courtesy switch signal / ON or OFF

ON: Back door open

OFF: Back door closed

*1: w/ Power Back Door System
*2: w/o Power Back Door System

OK:

The display is as specified in the normal condition column.

Result	Proceed to
NG	A
OK (w/ Power Back Door System)	B
OK (w/o Power Back Door System)	C

REPLACE POWER BACK DOOR ECU (POWER BACK DOOR MOTOR UNIT)

REPLACE BACK DOOR CLOSER ECU (MULTIPLEX NETWORK DOOR ECU)

2.	INSPECT BACK DOOR LOCK ASSEMBLY (BACK DOOR COURTESY SWITCH)

(a) Remove the back door lock assembly (See page ).

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

Standard Resistance:

Back Door Courtesy Switch

Tester Connection	Condition	Specified Condition
3 (CTY) - 4 (E)	Open-latch	Below 1 Ω
3 (CTY) - 4 (E)	Half-latch	Below 1 Ω
3 (CTY) - 4 (E)	Full-latch	10 kΩ or higher
3 (CTY) - 4 (E)	Over-latch	10 kΩ or higher

REPLACE BACK DOOR LOCK ASSEMBLY

3.	CHECK HARNESS AND CONNECTOR (BACK DOOR LOCK - POWER BACK DOOR ECU OR BACK DOOR CLOSER ECU)

(a) w/ Power Back Door System

(1) Disconnect the R1 back door lock assembly connector and L20 power back door ECU connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
R1-3 (CTY) - L20-20 (FUL)	Always	Below 1 Ω
R1-4 (E) - Body ground	Always	Below 1 Ω
R1-3 (CTY) - Body ground	Always	10 kΩ or higher

Text in Illustration

Front view of wire harness connector

(to Back Door Lock)

Front view of wire harness connector

(to Power Back Door ECU)

(b) w/o Power Back Door System

(1) Disconnect the R1 back door lock assembly connector and L21 back door closer ECU connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
R1-3 (CTY) - L21-6 (FUL)	Always	Below 1 Ω
R1-4 (E) - Body ground	Always	10 kΩ or higher
R1-3 (CTY) - Body ground	Always	10 kΩ or higher

Text in Illustration

Front view of wire harness connector

(to Back Door Lock)

Front view of wire harness connector

(to Back Door Closer ECU)

Result	Proceed to
NG	A
OK (w/ Power Back Door System)	B
OK (w/o Power Back Door System)	C

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE POWER BACK DOOR ECU (POWER BACK DOOR MOTOR UNIT)

REPLACE BACK DOOR CLOSER ECU (MULTIPLEX NETWORK DOOR ECU)

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