Lost Communication With Yaw Rate Sensor Module
Your vehicle's computer lost connection with the sensor that measures how fast the car is rotating around its vertical axis, like losing radio contact with a spinning gyroscope. This typically affects stability control systems that keep the car stable during turns and emergency maneuvers.
The ECU monitors yaw rate sensor data to detect vehicle rotation and adjust brake force and engine power to maintain stability. The sensor sends a continuous CAN bus signal with rotation rates in degrees per second. Loss of this signal for more than a few milliseconds triggers the fault code.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| CAN bus signal timeout | Active signal received every 10-20 ms | No signal received for >100 ms |
| Yaw rate plausibility | -180 to +180 degrees/second | Signal dropout or implausible values |
Code U0123 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, U0123 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.