Toyota 4Runner: Back Door Entry Lock and Unlock Functions do not Operate

Toyota 4Runner Service Manual / Vehicle Interior / Theft Deterrent / Keyless Entry / Smart Key System(for Entry Function) / Back Door Entry Lock and Unlock Functions do not Operate

DESCRIPTION

When the back door entry lock and unlock functions do not operate, one of the following may be malfunctioning: 1) the power door lock control system, 2) the electrical key antenna (outside luggage) or 3) the 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.
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.	CHECK WAVE ENVIRONMENT

(a) Bring the electrical key transmitter approximately 0.3 m (0.984 ft.) from the electrical key antenna (outside luggage) and perform an entry back door unlock function check (See page ).

NOTICE:

If the key is brought within 0.2 m (0.656 ft.) of the rear bumper, communication may not possible.

HINT:

If the inspection result is that the problem only occurs in certain locations or at certain times of day, the possibility of wave interference is high. Also, added vehicle components may cause wave interference. If installed, remove them and perform the operation check.

OK:

Entry function operates normally.

AFFECTED BY WAVE INTERFERENCE

3.	CHECK ELECTRICAL KEY ANTENNA IN KEY DIAGNOSTIC MODE

(a) Check the following antenna in the key diagnostic mode (See page ).

(1) Check the electrical key antenna (outside luggage).

When the electrical key transmitter is brought within 0.7 to 1.0 m (2.30 to 3.28 ft.) of the electrical key antenna (outside luggage), check that the wireless door lock buzzer sounds.

OK:

Wireless door lock buzzer sounds.

REPLACE CERTIFICATION ECU

4.	CHECK HARNESS AND CONNECTOR (ELECTRICAL KEY ANTENNA - CERTIFICATION ECU)

(a) Disconnect the N21 antenna connector.

(b) Disconnect the F78 ECU connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
N21-1 (CLG5) - F78-19 (CLG8)	Always	Below 1 Ω
N21-2 (CLGB) - F78-20 (CG8B)	Always	Below 1 Ω
F78-19 (CLG8) - Body ground	Always	10 kΩ or higher
F78-20 (CG8B) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	INSPECT ELECTRICAL KEY ANTENNA (OUTSIDE LUGGAGE)

(a) Remove the electrical key antenna (outside luggage) (See page ).

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
1 (CLG5) - 2 (CLGB)	Always	Below 1 Ω

REPLACE CERTIFICATION ECU

REPLACE ELECTRICAL KEY ANTENNA (OUTSIDE LUGGAGE)

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