Toyota 4Runner: Driver Side Door Entry Unlock Function does not Operate

Toyota 4Runner Service Manual / Vehicle Interior / Theft Deterrent / Keyless Entry / Smart Key System(for Entry Function) / Driver Side Door Entry Unlock Function does not Operate

DESCRIPTION

If the driver side door entry unlock function does not operate but the entry lock function operates, the communication line between the vehicle and electrical key transmitter is normal. The part at fault may be an unlock sensor circuit (front door outside handle assembly [for driver side] → certification ECU).

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

The smart key system (for Entry Function) uses a multiplex communication system (LIN communication system) and the CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting (See page ). Troubleshoot the smart key
system (for Entry Function) after confirming that the communication systems are functioning properly.
When using the Techstream with the engine switch off to troubleshoot: Connect the Techstream to the DLC3 and turn a courtesy light switch on and off at 1.5-second intervals until communication between the Techstream and vehicle begins.
Check that there are no electrical key transmitters in the vehicle.
Before performing the inspection, check that DTC B1242 (wireless door lock control) is not output (See page
).
When checking the entry lock operation multiple times, the lock operation may be limited to 2 consecutive operations depending on the settings. In order to perform the entry lock operation 3 or more times, an unlock operation must be performed once (any type of unlock operation is sufficient). However, only consecutive entry lock operations are limited. Using the wireless lock or other types of lock operations, it is possible to perform consecutive lock operations without this limitation.
Before replacing the certification ECU, refer to the engine immobiliser system (w/ Smart Key System) (See page
).

PROCEDURE

1.	CHECK POWER DOOR LOCK OPERATION

(a) When the door control switch on the multiplex network master switch assembly is operated, check that the doors unlock and lock according to the switch operation (See page ).

OK:

Door locks operate normally.

GO TO POWER DOOR LOCK CONTROL SYSTEM

2.	READ VALUE USING TECHSTREAM (DOOR LOCK POSITION SWITCH)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

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

(e) Read the Data List according to the display on the Techstream.

Main Body

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
FL Door Lock Pos	Front LH side door lock position switch signal / UNLOCK or LOCK	UNLOCK: Front LH side door unlocked LOCK: Front LH side door locked	-

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

FL Door Lock Pos

Front LH side door lock position switch signal / UNLOCK or LOCK

UNLOCK: Front LH side door unlocked

LOCK: Front LH side door locked

OK:

On the Techstream screen, the display changes between LOCK and UNLOCK as shown in the chart above.

GO TO POWER DOOR LOCK CONTROL SYSTEM (Proceed to Only Driver Door Lock/Unlock Functions do not Operate)

3.	READ VALUE USING TECHSTREAM (UNLOCK SENSOR)

(a) Using the Techstream, read the Data List (See page ).

Smart Key

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
D-Door Touch Sensor	Driver side door unlock sensor / ON or OFF	ON: Driver side door unlock sensor touched OFF: Driver side door unlock sensor not touched	-

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

D-Door Touch Sensor

Driver side door unlock sensor / ON or OFF

ON: Driver side door unlock sensor touched

OFF: Driver side door unlock sensor not touched

OK:

"ON" (unlock sensor is touched) and "OFF" (unlock sensor is not touched) appear on the screen.

REPLACE CERTIFICATION ECU

4.	CHECK HARNESS AND CONNECTOR (FRONT DOOR OUTSIDE HANDLE - CERTIFICATION ECU)

(a) Disconnect the M1 handle connector.

(b) Disconnect the F79 ECU connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
M1-4 (SENS) - F79-20 (SEN1)	Always	Below 1 Ω
F79-20 (SEN1) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	CHECK FRONT DOOR OUTSIDE HANDLE ASSEMBLY (FOR DRIVER SIDE)

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

Text in Illustration

Component with harness connected

(Certification ECU)

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
F79-20 (SEN1) - F79-15 (E)	Engine switch off, all doors locked, key not sufficiently close to vehicle and unlock sensor (for driver side) off → on	Pulse generation → Below 2 V

REPLACE CERTIFICATION ECU

REPLACE FRONT DOOR OUTSIDE HANDLE ASSEMBLY (FOR DRIVER SIDE)

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