ESP_a021_WSSGeneralVDiffFault
ABS (anti-lock braking system) disabled
What does the ESP_a021_WSSGeneralVDiffFault alert mean?
Wheel Speed Sensor: General Fault.
What you'll see in your Tesla
- ABS (anti-lock braking system) disabled
- Drive with caution
What triggers it
If the difference between maximum and minimum wheel speed related to a reference speed exceeds 5%. A generic wheel speed sensor fault is set if no wheel specific fault could be determined. During system mode ABS and backup-EBD (Electr. Brake Force Distribution) and below 20 kilometers per hour the deviation is 6 kilometers per hour for velocities < 100 kilometers per hour and 6% for a velocity > 100 kilometers per hour.
When it clears
1.) Open circuit in the WSS line 2.) Short circuit to + voltage in the WSS line 3.) Short circuit to GND in WSS line 4.) WSS dislodging from bracket 5.) Input amplifier in ECU faulty 6.) tooth wheel missing 7.) WSS not installed 8.) too great airgap 9.) incorrect tooth count
Potential impact
Will disable VDC/TC and degrade ABS
Affected models
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Alerts like this reach MyTeslaMate through your car's Tesla telemetry API. MyTeslaMate logs every alert your Tesla reports and turns it into readable history and real-time notifications — hosted TeslaMate with no server to run.