Push Switch / Key Unlock Warning Switch Malfunction (B2780)
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. |
|
CAUTION / NOTICE / HINT
NOTICE:
When the transponder key ECU assembly is replaced, refer to Registration (See page .gif)
).
PROCEDURE
CLEAR DTC
(a) Clear the DTCs (See page ).
|
.gif)
CHECK FOR DTC
(a) Check for DTCs (See page ).
OK:
DTC B2780 is not output.
| OK | .gif) | USE SIMULATION METHOD TO CHECK |
|
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 |
Not pushed |
10 kΩ or higher |
| NG | | REPLACE UNLOCK WARNING SWITCH ASSEMBLY |
|
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.
(c) Measure the resistance according to the value(s) in the table below.
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 |
| OK | | REPLACE TRANSPONDER KEY ECU ASSEMBLY |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
Test yourself
A quick Toyota 4Runner quiz: every answer comes with an explanation and a link to the manual page.