DTC B2780 Push Switch / Key Unlock Warning Switch Malfunction |
| DTC No. | DTC Detection Condition | Trouble Area |
| B2780 | "Unlock warning switch ON" is not detected when ignition switch is ON. |
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| 1.READ VALUE USING INTELLIGENT TESTER (KEY SWITCH) |
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the tester on.
Enter the following menus: Body / Immobiliser / Data List.
According to the display on the tester, read the Data List.
| Tester Display | Measurement Item/Range | Normal Condition | Diagnostic Note |
| Key SW | Unlock warning switch signal/ON or OFF | ON: Key is in ignition key cylinder OFF: No key is in ignition key cylinder | - |
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| OK | ||
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| 2.INSPECT UNLOCK WARNING SWITCH |
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Remove the unlock warning switch (Click here).
Measure the resistance according to the value(s) in the table below.
| Tester Connection | Switch Condition | Specified Condition |
| 1 - 2 | Switch pushed (Key set) | Below 1 Ω |
| Switch free (Key removed) | 10 kΩ or higher |
Reinstall the unlock warning switch.
| *1 | Component without harness connected (Unlock Warning Switch) |
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| OK | |
| 3.CHECK HARNESS AND CONNECTOR (UNLOCK WARNING SWITCH - BODY GROUND) |
Disconnect the D18 unlock warning switch connector.
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Measure the resistance according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
| D18-1 - Body ground | Always | Below 1 Ω |
Reconnect the unlock warning switch connector.
| *1 | Front view of wire harness connector (to Unlock Warning Switch) |
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| OK | |
| 4.CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - UNLOCK WARNING SWITCH) |
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Disconnect the D29 transponder key ECU connector.
Disconnect the D18 unlock warning switch connector.
Measure the resistance according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
| D29-3 (KSW) - D18-2 | Always | Below 1 Ω |
| D18-1 - Body ground | Always | 10 kΩ or higher |
Reconnect the transponder key ECU connector.
Reconnect the unlock warning switch connector.
| *1 | Front view of wire harness connector (to Unlock Warning Switch) |
| *2 | Front view of wire harness connector (to Transponder Key ECU) |
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| OK | ||
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