U0122 code meaning
Lost Communication With Vehicle Dynamics Control Module
Network system Generic code U01xx codes Check engine light
What U0122 means
U0122 tells you that a networked controller, often the engine or hybrid ECU, has stopped receiving the cyclic frames of the stability control unit (ESC/VSC/ASC, usually combined with the ABS hydraulic unit). Mitsubishi's 2023 Outlander PHEV documents it in the PHEV-ECU: with 10–16 V present for at least 5 s and the motor switch on, a broken link to the ABS/ASC unit lasting 2 s or more stores U0122-00, and Mitsubishi verifies the repair with an OBD-II test drive pattern. Saab's 9-5 code list names the partner Vehicle Stability Control Module, and Subaru released ECM software for the 2019 Ascent that changes how its ECM detects U0122. U0121 and U0129 point at the ABS and brake modules instead. Stability and traction aids usually switch off.
U0122 at a glance
- Check engine lightYes, usually on
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0122
- ESC, traction control and ABS warning lamps on
- Stability and traction control unavailable
- MIL on in some vehicles (engine or hybrid ECU stores the code)
Common causes of U0122
- Most likelyMissing fuse, supply or ground at the stability/ABS unit
- PossibleDamaged CAN wiring or faulty gateway between the bus segments
- PossibleReceiving controller software reports the loss too eagerly (update exists, e.g. Subaru)
- Less likelyStability control module internally faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Vehicle dynamics moduleCAN bus wiring
What each part of U0122 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 22 | The exact fault in that area. |
What to do next
- Note U0122 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 U0122
What does U0122 mean?
U0122 means "Lost Communication With Vehicle Dynamics Control Module". U0122 tells you that a networked controller, often the engine or hybrid ECU, has stopped receiving the cyclic frames of the stability control unit (ESC/VSC/ASC, usually combined with the ABS hydraulic unit). It is a generic code, so it means the same on every make.
Is it safe to drive with U0122?
Drive gently and only to a workshop. With U0122 the car can go into limp mode (reduced power) to protect itself.
Will U0122 fail an emissions test?
U0122 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 U0122 to fix?
Difficulty: medium. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will U0122 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.