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U0122 — Lost Communication with Vehicle Dynamics Control Module

CautionNetwork/CANLimp to the next safe stop

Seen on: Heavy Truck

Lost Communication with Vehicle Dynamics Control Module. Common causes: VDC/stability module offline.

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How serious is it?

Caution. Limp to the next safe stop.

Most likely causes

  1. VDC/stability module offline
  2. Module power fault
  3. CAN wiring

First moves (roadside)

  1. Check VDC module power and CAN connections

FAQ

What does U0122 mean?

Lost Communication with Vehicle Dynamics Control Module. Common causes: VDC/stability module offline.

How serious is U0122?

Caution — Limp to the next safe stop.

What's the most likely cause of U0122?

The most common cause is: VDC/stability module offline. Other possibilities include Module power fault; CAN wiring.

Can I keep driving with U0122?

Limp to the next safe stop. When in doubt, get a qualified mobile diesel tech on the truck before continuing.

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Find a mechanic or related guides

General diagnostic guidance for diesel engines (Cummins, Detroit, PACCAR, Volvo, Mack and more). Not a substitute for a scan-tool diagnosis on your specific truck.