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.

2009 Toyota Prius BaseFACTORY OEM SERVICE PROCEDURE

Window Defogger System: Inspection

CHECK STEERING PAD SWITCH

Remove the horn button (See REMOVAL ).
Disconnect the connector as shown in Fig 1.

Fig 1: Disconnecting Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 2: Identifying Steering Pad Switch Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the resistance of the switch.

Standard resistance

TERMINALS RESISTANCE SPECIFICATION

Tester Connection	Switch Condition	Specified Condition
3 (AC1) - 7 (EAC)	OFF	29 to 31 kΩ
3 (AC1) - 7 (EAC)	ON	290 to 305 Ω

If the result is not as specified, replace the switch.

Chapter Navigation

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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.