DTC    B2780    Push Switch / Key Unlock Warning Switch Malfunction

for Preparation Click here


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
DTC Output Confirmation Operation
B2780
The unlock warning switch assembly is not detected as being on when the ignition switch is ON (1 trip detection logic*).
  1. Unlock warning switch assembly
  2. Harness or connector
  3. Transponder key ECU assembly
Insert the key into the ignition key cylinder.
  1. *: Only output while a malfunction is present.

Vehicle Condition and Fail-safe Operation when Malfunction Detected 
Vehicle Condition when Malfunction Detected
Fail-safe Operation when Malfunction Detected
Engine cannot be started.
-

Related Data List and Active Test 
DTC Code
Data List and Active Test
B2780
Key SW

WIRING DIAGRAM


C239010E03


INSPECTION PROCEDURE

NOTICE:
  1. When replacing the transponder key ECU assembly, refer to the Service Bulletin.
  2. After performing repairs, perform the operation that fulfills the DTC output confirmation operation, and then confirm that no DTCs are output again.
1.CLEAR DTC
  1. Clear the DTCs (Click here).


NEXT


2.CHECK FOR DTC
  1. Check for DTCs (Click here).

    OK:
    DTC B2780 is not output.


NG
Go to step 3
OK

USE SIMULATION METHOD TO CHECK (Click here)  

3.INSPECT UNLOCK WARNING SWITCH ASSEMBLY


    B274206E01
  1. Remove the unlock warning switch assembly.

  1. 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
    Not pushed
    10 kΩ or higher
    Text in Illustration 
    *a
    Pushed
    *b
    Not pushed


NG
REPLACE UNLOCK WARNING SWITCH ASSEMBLY
OK


4.CHECK HARNESS AND CONNECTOR (UNLOCK WARNING SWITCH - TRANSPONDER KEY ECU AND BODY GROUND)
  1. Disconnect the U1 unlock warning switch assembly connector.

  1. Disconnect the T21 transponder key ECU assembly connector.

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

    Standard Resistance:
    Tester Connection
    Condition
    Specified Condition
    U1-1 - T21-3 (KSW)
    Always
    Below 1 Ω
    U1-1 or T21-3 (KSW) - Body ground
    Always
    10 kΩ or higher
    U1-2 - Body ground
    Always
    Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE TRANSPONDER KEY ECU ASSEMBLY