ESP-A139
ESP_a139_steeringAngleWrongSign
Also written as ESP_A139 / ESP A139 / ESP_a139_steeringAngleWrongSign / esp_a139_steeringanglewrongsign
Why does the exact Tesla alert ID matter?
Record the exact alert ID, including underscores, suffixes, and companion alerts. Tesla alerts that look similar can point to different modules, timestamps, and service procedures.
What does ESP-A139 mean?
Tesla alert code in the Electronic Stability Program (ESP) module. This monitoring detects a wrong sign of steering angle signal. The yaw rate calculated from steering angle and the yaw rate calculated from the wheel speed sensors are compared. If the measured yaw rate fits to the model yaw rate positive integrals (IVzLwVA and IVzLwHA) are calculated but if the negative values fits the integrals will become negative. A fault is determined if the integral value is negative and forward driving is recognized. This fault will cause a release test in the following ignition cycle to assure that the sensor is build in correctly. This fault can also be caused by swapped WSS lines at one axle. It requires a release check in the following ignition cycle to prevent system release when the fault is still present. The conditions for release is positive integrals (IVzLwVA and IVzLwHA) > +180 deg. UI_odo message integrity check failed ESP is providing hydraulic boost due to power brakes failure ESP has lost communication with the iBooster, or iBooster has lost the ability to support brake boost Check iBooster status and traffic on the PARTY and CHASSIS bus Brake boost functionality degraded Yawrate signal received from RCM exceeds message latency specification
Original Description
This monitoring detects a wrong sign of steering angle signal. The yaw rate calculated from steering angle and the yaw rate calculated from the wheel speed sensors are compared. If the measured yaw rate fits to the model yaw rate positive integrals (IVzLwVA and IVzLwHA) are calculated but if the negative values fits the integrals will become negative. A fault is determined if the integral value is negative and forward driving is recognized. This fault will cause a release test in the following ignition cycle to assure that the sensor is build in correctly. This fault can also be caused by swapped WSS lines at one axle. It requires a release check in the following ignition cycle to prevent system release when the fault is still present. The conditions for release is positive integrals (IVzLwVA and IVzLwHA) > +180 deg. UI_odo message integrity check failed ESP is providing hydraulic boost due to power brakes failure ESP has lost communication with the iBooster, or iBooster has lost the ability to support brake boost Check iBooster status and traffic on the PARTY and CHASSIS bus Brake boost functionality degraded Yawrate signal received from RCM exceeds message latency specification
Affected Tesla Models
What You May Notice
- ESP-A139 may appear with another Tesla alert in the Electronic Stability Program (ESP) system.
- The vehicle may limit charging, driving, comfort, or safety features depending on the active alerts.
- The alert may clear after sleep, but recurring alerts should be treated as service-relevant.
How to Diagnose and Resolve
- 1 Reboot the vehicle by holding both scroll wheels
- 2 Check for available OTA software updates
- 3 If alert persists after reboot, schedule a service appointment
Severity Notes
ESP-A139 is an Alert in the Electronic Stability Program system. Confirm the vehicle screen and Tesla app show no driving or charging restrictions, and schedule service if the alert returns.