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.

2018 Tesla Model S 100DFACTORY OEM SERVICE PROCEDURE

Alert Code: TAS_w121_maxDutyFL

Signal Name	TAS_w121_maxDutyFL
Shown to Customer	True
Debug Text	TAS_w121_maxDutyFL
User Message	Air Suspension Temporarily Unavailable:
Chime/Notification Behavior	Behavior Name: CLUSTER_SINGLE_CHIME_NOTIFICATION Shown on Cluster: False Sound Repeated: False Sound Name: ALERT_SOUND_CHIME Icon Type: ALERT_ICON_NOTIFICATION
Intent	To indicate the FL valve has reached its duty-cycle (on-time) limit.
Set Condition	The FL valve reaches its duty-cycle limit.
Clear Condition	The FL valve duty-cycle drop below a separate duty-cycle limit.
Potential Impact	The FL valve is temporarily unavailable. This prevents normal operation of the air suspension.

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.