Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2006 Toyota Sienna AWD V6-3.3L (3MZ-FE)FACTORY OEM SERVICE PROCEDURE
Unlock Warning Switch Circuit
Unlock Warning Switch Circuit
DESCRIPTION
The unlock warning switch detects if the key is in the ignition key cylinder.
The unlock warning switch turns on when the key is inserted into the ignition key cylinder and turns off when the key is removed from the cylinder.
The body ECU is connected to the unlock warning switch via terminal KSW and key detection status signals are input to the ECU.
The body ECU applies voltage to the unlock warning switch via terminal KSW. When the unlock warning switch is on (there is continuity between the switch terminals), a signal indicating that the key is in the ignition key cylinder is input to the body ECU. When the switch is off (there is no continuity between the switch terminals), a signal indicating that the key is not in the cylinder is input.
INSPECTION PROCEDURE
DESCRIPTION
The unlock warning switch detects if the key is in the ignition key cylinder.
The unlock warning switch turns on when the key is inserted into the ignition key cylinder and turns off when the key is removed from the cylinder.
The body ECU is connected to the unlock warning switch via terminal KSW and key detection status signals are input to the ECU.
The body ECU applies voltage to the unlock warning switch via terminal KSW. When the unlock warning switch is on (there is continuity between the switch terminals), a signal indicating that the key is in the ignition key cylinder is input to the body ECU. When the switch is off (there is no continuity between the switch terminals), a signal indicating that the key is not in the cylinder is input.
Wiring Diagram:
Step 1:
Step 1(continued)-3:
INSPECTION PROCEDURE
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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