OBD-II trouble code
U0133: Lost Communication With Active Roll Control Module
The active roll control (anti-roll) module has gone silent on the vehicle network — other modules expect its messages and aren't receiving them.
Quick facts
- System
- Network
- Category
- Network Communication
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $50 – $900
- DIY difficulty
- Advanced DIY
What does U0133 mean?
Vehicles with active roll control use hydraulic or electromechanical actuators on the anti-roll bars to reduce body lean in corners, managed by a dedicated control module on the CAN network. U0133 sets when other modules stop receiving that module's messages — it has gone silent, not necessarily failed: it may have lost power or ground, its CAN wiring may be damaged, or the module itself may be dead.
As with all lost-communication codes, the fault is usually upstream of the module's brain. The classic causes, in rough order: a blown fuse or corroded power/ground feed, connector damage or corrosion (suspension modules often live in harsh, wet locations), damaged CAN bus wiring, and only then a failed module. Low battery voltage during cranking can also set U-codes spuriously — always check basics before deep diagnosis.
Expect the roll-control system to default to a safe passive state: the car still drives, with more body roll and a suspension/stability warning on the dash. This code appears only on vehicles actually equipped with active roll control — a scan tool that can address the module directly is the fastest way to confirm whether it's truly offline.
Common causes
- Blown fuse or lost power/ground to the roll control module
- Corroded or damaged module connector
- Damaged CAN bus wiring to the module
- Failed active roll control module
- Low system voltage during cranking (can set the code spuriously)
Symptoms
- Suspension/stability warning light or message
- Noticeably more body lean in corners (system in passive fallback)
- Code stored in one or more other modules
- Vehicle otherwise drives normally
Diagnostic steps
- 1.Verify the vehicle actually has active roll control — this code only applies to equipped vehicles.
- 2.Check battery/charging health first; low voltage sets network codes spuriously.
- 3.Try to communicate with the roll control module directly with a scan tool — no response confirms it's offline.
- 4.Check the module's fuses, power, and ground feeds.
- 5.Inspect the module connector and CAN wiring for corrosion or damage (these modules often live in exposed locations).
- 6.If power, ground, and network wiring are good and it still won't respond, replace and program the module.
Repair cost
$50 – $900
A fuse, ground, or connector repair is cheap. If the module itself is dead, replacement plus programming typically runs $400-$900 depending on the make. Diagnosis is the main cost when the fault is intermittent wiring.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with control module replacement & programming preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
This is an advanced DIY job. It typically requires specialty tools, scan-tool access, lifting equipment, or careful sequencing to avoid causing new failures. Plan for extended downtime and have a backup vehicle. Most owners are better served by a shop that has done this repair before.