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.
2004 Lexus SC 430FACTORY OEM SERVICE PROCEDURE
Ignition Switch Test
WARNING: This page is about a different car, the 2004 Lexus LS 430, 2003 Lexus LS 430, and 2002 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.
Using ohmmeter, measure resistance between specified terminals. For resistance specifications, see IGNITION SWITCH CONNECTOR RESISTANCE . If the resistance is not as specified, replace switch.
IGNITION SWITCH CONNECTOR RESISTANCE
| Switch Position | Terminal No. | Resistance (Ohm) |
|---|---|---|
| LOCK | All | 10k or higher |
| ACC | 1 & 3 | Below 1 |
| ON | 1 & 2, 1 & 3, 5 & 6 | Below 1 |
| START | 1 & 2, 4 & 5, 5 & 6 | Below 1 |
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.