Tesla 'ESP_a118' Stability Control Reduced — Fix Guide

What Does This Error Mean?

Tesla ESP_a118 reads 'Stability control reduced'.
The Electronic Stability Program — which intervenes when the car detects a skid — has lost confidence in one of the inputs it relies on (wheel speed sensors, yaw rate sensor, or steering angle sensor) and dropped to a reduced-function mode.
The car still drives normally in dry conditions.
It is not safe to push the car hard until ESP is restored.

Affected Models

Tesla Model 3
Tesla Model Y
Tesla Model S
Tesla Model X

Common Causes

Wheel speed sensor reading inconsistent (often after a tyre change with the wheel speed harness disturbed)
Steering angle sensor uncalibrated after an alignment
Yaw rate sensor briefly failed self-test
ABS module fault that disables ESP as a side effect
Brake-by-wire system showing degraded performance

How to Fix It

Note any other alerts.

ESP_a118 rarely shows alone.
Check for ABS warnings, traction control, or steering-related alerts on the screen.
If multiple alerts are present, the underlying issue is the sensor or module they all share — not ESP itself.
Restart the car at a safe stop.

Park, hold both scroll wheels for 10 seconds.
Wait for the screen to come back on (about a minute).
Drive again.
A self-test issue often clears on the second key cycle.
Drive a short distance straight.

Some sensors recalibrate during a drive.
Drive 100 metres in a straight line on a flat surface, then make several gentle turns left and right at low speed.
The steering angle sensor needs to see the wheels at zero and at angle to learn its centre point — alignments and tyre changes can disturb this.
Check the tyres.

Different tyre diameters on the same axle confuse the wheel speed sensors.
If you recently rotated, swapped, or replaced just one tyre, check that all four match in size and tread depth.
A 6 mm tread vs 2 mm tread on the same axle can trigger ESP_a118 because wheel speeds don't agree.
If it persists, book service.

ESP_a118 that won't clear with a restart and a calibration drive is a real fault — wheel speed sensor failure is the most common.
Tesla service can read the actual fault code from the ABS module and replace the affected sensor.
It's a $400-$600 repair on most cars; unsafe to ignore.

When to Call a Professional

ESP keeps the car controllable in emergencies.
Driving with ESP_a118 in the rain or snow is risky.
If you cannot clear it with a restart, book service before driving in slippery conditions.

Frequently Asked Questions

Can I disable the alert if the car still drives fine?

No.
And you shouldn't want to.
ESP_a118 means the system that catches a skid before it becomes a crash is not at full strength.
Dry roads are forgiving, but wet leaves, ice, or sudden swerves are exactly when ESP earns its keep.
Get it fixed before you need it.