OBD-II code · Network

U0139 Lost Communication with Active Roll Control Module

The active anti-roll bar / dynamic chassis controller has dropped off the bus. The vehicle behaves as if the system is disabled; rolling motion is not actively counteracted.

Is it safe to drive with U0139?

Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.

Common causes

  • Most likelyActive roll module unpowered
  • Less likelyGateway module routing CAN messages incorrectly
  • Less likelyCAN terminating resistor (120 Ω) drifted out of spec

Symptoms

  • Multiple warning lights may illuminate
  • Affected modules may go into limp mode or shut down
  • Specific functions inoperative depending on module
  • Diagnostic tools may show communication faults

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
0.5–3 h
Emissions test
Usually unaffected
Parts involved
Active Roll Module, Can Bus Wiring

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.