U0122Lost Communication With Vehicle Dynamics Control Module
- Generic OBD-II code · Network
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- 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.
- What you may notice
- 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)
- Likely causes
- 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)
- RareStability control module internally faulty
- Repair
- Medium · Usually a job for a workshop.Typical cost: €60 – €1,800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.