Toyota 4Runner: Push Switch / Key Unlock Warning Switch Malfunction (B2780)

Toyota 4Runner Service Manual / Vehicle Interior / Theft Deterrent / Keyless Entry / Engine Immobiliser System(w/o Smart Key System) / Push Switch / Key Unlock Warning Switch Malfunction (B2780)

DESCRIPTION

This DTC is stored if the transponder key ECU assembly does not detect that the unlock warning switch assembly is on even when the ignition switch is ON. Under normal conditions, the unlock warning switch assembly is on when the ignition switch is ON.

DTC Code	DTC Detection Condition	Trouble Area
B2780	The unlock warning switch assembly is not detected as being on when the ignition switch is ON.	Transponder key ECU assembly Unlock warning switch assembly Harness or connector

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

When the transponder key ECU assembly is replaced, refer to Registration (See page ).

PROCEDURE

CLEAR DTC

(a) Clear the DTCs (See page ).

2.	CHECK FOR DTC

(a) Check for DTCs (See page ).

OK:

DTC B2780 is not output.

USE SIMULATION METHOD TO CHECK

3.	INSPECT UNLOCK WARNING SWITCH ASSEMBLY

(a) Remove the unlock warning switch assembly (See page ).

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
1 - 2	Pushed	Below 1 Ω
1 - 2	Not pushed	10 kΩ or higher

REPLACE UNLOCK WARNING SWITCH ASSEMBLY

4.	CHECK HARNESS AND CONNECTOR (UNLOCK WARNING SWITCH - TRANSPONDER KEY ECU AND BODY GROUND)

(a) Disconnect the F18 switch connector.

(b) Disconnect the F34 ECU connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
F34-3 (KSW) - F18-1	Always	Below 1 Ω
F34-3 (KSW) or F18-1 - Body ground	Always	10 kΩ or higher
F18-2 - Body ground	Always	Below 1 Ω

REPLACE TRANSPONDER KEY ECU ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

Problem Symptoms Table

PROBLEM SYMPTOMS TABLE HINT: Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are lis ...

Data List / Active Test

DATA LIST / ACTIVE TEST 1. READ DATA LIST HINT: Using the Techstream to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing ...

Other materials about Toyota 4Runner:

Reassembly
REASSEMBLY PROCEDURE 1. INSTALL FRONT OIL PUMP OIL SEAL (a) Using SST and a hammer, tap in a new oil seal. SST: 09350-30020 09351-32140 HINT: Make sure the oil seal end is flush with the outer edge of the pump body. ...

System Diagram
SYSTEM DIAGRAM Communication Table Sender Receiver Signal Line ECM Stabilizer control ECU Engine type information Gear information Drive train informat ...