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.
1998 Lexus LS 400FACTORY OEM SERVICE PROCEDURE
Key Unlock Warning Switch Circuit
- Check Key Unlock Warning Switch
Check key unlock warning switch. See STEERING COLUMN SWITCHES article. If switch is okay, go to next step. Replace switch as necessary. Retest system operation. - Check Circuits
Check circuits for faults between key unlock warning switch and body control ECU No. 2. See WIRING DIAGRAMS. Repair or replace as necessary. If circuits are okay, go to next test listed in appropriate TROUBLE SHOOTING SYMPTOMS table.
Factory Service Tools
Use the Manual With the Right Hardware
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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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