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.
1997 Lexus SC 400FACTORY OEM SERVICE PROCEDURE
Circuit Test
- Remove all necessary components to access theft deterrent ECU. See ELECTRICAL COMPONENT LOCATIONS under DESCRIPTION & OPERATION. Disconnect electrical connectors from theft deterrent ECU. Shift transmission into Neutral (or press clutch pedal to floor).
- While holding ignition switch in START position, measure voltage between body ground and terminal SRLY of theft deterrent ECU connector (harness side). See Fig 1. If 10-14 volts is measured, replace theft deterrent ECU. If 10-14 volts is not measured, check for faulty starter relay, park/neutral position switch (clutch switch on M/T), or wiring harness.
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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