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U0133 Lost Communication With Active Roll Control Module

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U0133 indicates that the active roll control module, which drives hydraulic or electromechanical anti-roll bars to reduce body lean in corners, no longer answers on the bus. No manufacturer publicly ties U0133 to that module: Saab's 2011 9-5 list uses the number for its air suspension control module instead, so older vehicles may interpret it differently. Systems of this kind exist, for instance on the Bentley Bentayga, where the adaptive suspension unit J775 acts as master for the roll stabiliser units J924 (front axle) and J1096 (rear axle) and their software must match (TPI 2055643). Invalid roll-module data is U0434; suspension modules A and B lose contact under U0132 and U0139. Expect a chassis warning and noticeably more body roll.

Likely causes

Fuse, supply, ground or CAN wiring of the roll control module faulty
Software of master and stabiliser units not compatible after a replacement (Bentley TPI 2055643)
Roll control module internally faulty

Symptoms

  • Chassis or suspension warning lamp
  • More body roll when cornering
  • Sport or dynamic driving modes unavailable

Repair estimate

DifficultyHardWorkshop job
Parts and labour€80–2,500
Time0.5–5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

active roll modulecan bus wiring

Related codes

U0434U0132U0139

References: law.cornell.edu, saabwisonline.com, static.nhtsa.gov, en.wikipedia.org.