U0123 code meaning
Lost Communication With Yaw Rate Sensor Module
What U0123 means
U0123 is stored when the stability controller or another listener misses the messages of a networked yaw rate sensor, the unit that measures how fast the car rotates around its vertical axis. Without that signal ESC cannot compare the actual turn with the steering input. No manufacturer explains U0123 in an openly accessible document; Ford merely lists it among the OBD codes of the 2014 Boss 302S. GM bulletin PIT5187A shows how such sensors are packaged today: yaw rate, inertia and multi-axis sensor are names for one combined module, which is why newer GM cars report it under U0125. Lateral acceleration has its own code U0124, invalid yaw data is U0513. Expect ESC and traction lamps on; driving remains possible.
U0123 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0123
- ESC and traction control warning lamps on
- Stability control switched off for the rest of the trip
- Often stored together with U0124 when both signals come from one housing
Common causes of U0123
- Most likelyLoose or corroded connector at the yaw rate sensor (often under the centre console or seat)
- PossibleFuse, supply or ground of the sensor module missing
- PossibleDamaged chassis CAN wiring to the sensor
- Less likelyYaw rate sensor module internally failed
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Yaw rate sensorCAN bus wiring
What each part of U0123 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 23 | The exact fault in that area. |
What to do next
- Note U0123 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about U0123
What does U0123 mean?
U0123 means "Lost Communication With Yaw Rate Sensor Module". U0123 is stored when the stability controller or another listener misses the messages of a networked yaw rate sensor, the unit that measures how fast the car rotates around its vertical axis. It is a generic code, so it means the same on every make.
Is it safe to drive with U0123?
U0123 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U0123 fail an emissions test?
U0123 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is U0123 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will U0123 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.