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.
2008 Lexus IS FFACTORY OEM SERVICE PROCEDURE
On-Vehicle Inspection
- INSPECT DEFOGGER RELAY (Marking: DEFOG)
- Measure the resistance of the DEFOG relay.
Standard Resistance
STANDARD RESISTANCETester Condition Condition Specified Condition 3 - 4 When battery voltage is not applied between terminals Below 1 Ω 3 - 5 When battery voltage is not applied between terminals 10 kΩ or higher 3 - 5 When battery voltage is applied to terminals 1 and 2 Below 1 Ω If the result is not as specified, replace the relay.
- Measure the resistance of the DEFOG relay.
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.