Damaged or corroded wiring and connectors in the CAN bus circuit between the yaw rate sensor module and the rest of the network.; Failed yaw rate sensor module, often due to internal electronics failure or water intrusion.; Blown fuse or poor power/ground connection supplying the yaw rate sensor module.; CAN bus wiring shorted to ground or to battery voltage, or an open circuit in the twisted pair.; A faulty module on the same CAN segment pulling the bus down and disrupting communication.; Software or calibration issue in the yaw rate sensor module requiring a reflash or relearn procedure.; Aftermarket accessories or improper electrical repairs that disturb the CAN bus wiring.

DTC codes / U01xx · Lost communication with a control module / U0123

U0123Lost Communication With Yaw Rate Sensor Module

Q: What does code U0123 mean?

Lost Communication With Yaw Rate Sensor Module. U0123 is a communication fault that sets when the vehicle's main control modules stop receiving data from the yaw rate sensor module over the controller area network (CAN) bus. The computer has detected a loss of the periodic messages that the yaw rate sensor normally broadcasts, not necessarily a failure of the sensor itself.

U0123 is a communication fault that sets when the vehicle's main control modules stop receiving data from the yaw rate sensor module over the controller area network (CAN) bus. The computer has detected a loss of the periodic messages that the yaw rate sensor normally broadcasts, not necessarily a failure of the sensor itself.

SystemNetwork

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaLost communication with a control module

Symptoms you may notice

Anti-lock brake system (ABS) warning light and electronic stability control (ESC) warning light illuminated on the dashboard.
Traction control and hill-start assist systems disabled, often with a message on the driver information display.
A stored U0123 code in multiple modules, sometimes accompanied by other U-codes for lost communication with the same module.
Often no symptoms besides the warning light, with normal braking and driving behavior in dry conditions.
In some vehicles, the speedometer, odometer, or cruise control may become inoperative if the yaw rate sensor shares data with those systems.
Intermittent warning light operation if the communication loss is caused by a loose connector or chafed wire.

Common causes, most likely first

Damaged or corroded wiring and connectors in the CAN bus circuit between the yaw rate sensor module and the rest of the network.
Failed yaw rate sensor module, often due to internal electronics failure or water intrusion.
Blown fuse or poor power/ground connection supplying the yaw rate sensor module.
CAN bus wiring shorted to ground or to battery voltage, or an open circuit in the twisted pair.
A faulty module on the same CAN segment pulling the bus down and disrupting communication.
Software or calibration issue in the yaw rate sensor module requiring a reflash or relearn procedure.
Aftermarket accessories or improper electrical repairs that disturb the CAN bus wiring.

How to diagnose and fix it

Verify the code with a scan tool that can read all modules and check for related U-codes and power/ground faults.
Inspect the yaw rate sensor module connector and wiring for corrosion, loose pins, or chafing, and repair as needed.
Check the fuse and relay supplying power to the yaw rate sensor module, and verify good ground connections.
Measure CAN bus resistance and voltage at the yaw rate sensor connector to confirm bus integrity and rule out a short or open.
If wiring and power are good, substitute a known-good yaw rate sensor module or perform a module swap to confirm the fault.
After repair, clear codes and perform a steering angle sensor and yaw rate sensor calibration or relearn as required by the manufacturer.
Road test the vehicle to confirm communication is restored and no warning lights return.

Yaw Rate Sensor Communication Traps

A U0123 code does not automatically mean the yaw rate sensor is bad; a single chafed CAN wire or a loose ground can set the same code and mimic a failed module.
Many vehicles set U0123 as a secondary code when the ABS module or another module on the same bus fails, so always check for other communication codes before condemning the yaw rate sensor.
Water intrusion into the yaw rate sensor connector or module housing is a common cause that visual inspection often misses, especially on vehicles with clogged sunroof drains or cowl leaks.
After replacing the yaw rate sensor, a calibration or relearn procedure is usually required; skipping it can leave the stability control system inoperative even though communication is restored.
Intermittent U0123 codes that appear only on rough roads or in wet weather often point to a wiring harness issue rather than an internal sensor failure.

Can I keep driving with U0123?

The vehicle is generally safe to drive with U0123 because the stability control and ABS may be disabled, but you should avoid hard braking, sharp evasive maneuvers, and slippery road conditions until the fault is repaired. If the warning light is accompanied by a loss of power steering assist or other critical systems, stop driving and have the vehicle towed.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.