By iCarsoft Official Store Technical Team, Automotive Diagnostics Editors · Updated October 14, 2026 · Technical sources checked
Quick Answer
U0133 records lost communication with active roll control module. It does not prove a failed module; preserve the full scan and use the VIN-specific network procedure before selecting a repair.
What Does the U0133 Code Mean?
The Autel official DTC table lists U0133 as Lost Communication with Active Roll Control Module. That terminology identifies the named message endpoint; it does not establish a vehicle-specific topology, threshold or failed part. The full fault record determines the test branch.
The Autel table names the Active Roll Control Module, an endpoint associated with vehicle body-control behavior, but does not define a common architecture. The missing message could be caused by power, ground, wake, connector or bus availability; it could also be a gateway/configuration condition. The code does not identify an active-roll actuator, hydraulic unit, sensor or controller as failed. Preserve vehicle stance, handling warnings, companion codes and history status.
Active-roll systems may interact with suspension and stability functions, so an ordinary scan result cannot replace the VIN-specific functional check. Distinguish U0133 from suspension-control and steering codes by the actual reporter and module name, not by the symptom alone. Active roll control may be integrated with suspension, stabilizer or body systems differently across platforms.
The code table does not identify hydraulic pressure, actuator position, sensor calibration or a safe drive condition. Compare the reporting module’s event with the current roll-control or stability warning and determine whether the named controller is present and reachable. A network branch that recovers after approved wake or configuration work still requires the manufacturer’s affected-system check.
Do not create a handling event to reproduce a communication code, and do not turn a shared symptom into a module replacement conclusion. The “active roll” wording also should not be rewritten as a generic anti-roll-bar or suspension diagnosis. Identify the controller named by the scan tool and whether the vehicle uses an integrated or separate roll-control architecture.
If the record is historical and the module is presently reachable, compare the timing with battery, software or network work. If the warning is current, retain the exact status and companion faults before any clear command. The manufacturer may require calibration or an active functional test after network recovery, but those steps are not supplied by the Autel table and must not be invented.
Keep the controller’s status and the stability system’s current warning separate in the final evidence. If the controller is reachable, compare stored and current status before any functional command; if it is not, prove external availability first. That order avoids turning a network record into an actuator verdict. Record the controller’s current access before calling the roll system unavailable. Record status.
The active-roll endpoint is distinct from U0132 suspension A and U0139 suspension B; symptom overlap does not make procedures interchangeable.
Autel AL519 PDF p.99 lists U0133 as Lost Communication with Active Roll Control Module. This is a generic endpoint label; it gives no universal active-roll hardware test or repair path.
Confirm whether the code is current and whether handling or suspension warnings exist. Prove the named module’s supply and network path under the VIN procedure; do not authorize an actuator or suspension assembly from U0133 alone. Complete the affected-system check before release. Confirm each conclusion against the current service record before authorizing work.
Save the full module wording and suffix before clearing; they can change the test path.
Separate U0133 from adjacent fault families
| Code | General description | Key distinction |
|---|---|---|
| U0133 | Lost Communication with Active Roll Control Module | The named message endpoint differs from the bus-off and body-module records below. |
| U0073 | Control Module Communication Bus A Off | A bus-off result is a different network condition; confirm the actual fault record. |
| U0140 | Lost Communication with Body Control Module | A body-network code is not interchangeable with this module-specific result. |
Record the complete U0133 description. The suffix, reporting module and companion faults can change the diagnostic path. Use the manufacturer's full wording and test procedure for the exact vehicle.
U0133 Symptoms and Likely Causes
Record U0133 symptoms and fault status; symptoms alone cannot identify a failed part.
Check whether companion faults share a proven cause.
Record the exact warning, when it appeared and which function changed; it is evidence, not proof of a failed controller.
Compare saved multi-module reports with supported live data; unavailable data does not identify the cause.
Preserve service history and inspect the disturbed branch first while treating timing as a clue.
Save every module's codes and status; a shared supply or network code can change the diagnostic order.
Practical cause-checking order
- Active-roll controller supply, ground or wake unavailable: Use the active-roll control module diagram to identify the required feed, ground and wake state. A missing response is a starting observation; the approved supply checks must determine whether the controller could operate in that state.
- Active-roll network branch or connector issue: Inspect the connector and communication branch identified for this VIN, especially any area disturbed during recent work. Document the failed terminal or wiring test instead of attributing every network record to one visible connector.
- Gateway or calibration/configuration state affecting the endpoint: Compare the fitted equipment, gateway route and current configuration with manufacturer information. A generic code label cannot show whether a route or software change is appropriate; use an applicable OEM instruction before changing either.
- Controller absent or not responding in the installed architecture: Compare the reporting receiver with direct access to the named controller. Record whether the condition is current, intermittent or stored, and repeat only the prescribed wake or verification sequence; do not use repeated battery resets as diagnosis.
- Internal controller fault only after external checks: Consider the named controller only after the applicable external checks support that conclusion. Save the evidence that excludes supply, connector, communication and configuration branches, and include required setup and functional verification in the proposed repair.
Did U0133 appear after recent battery, interior, module, harness or software work? Recheck the documented connections, parts and setup steps affected by that work. Record battery and software history; a post-repair code does not prove the new part is defective.
How Serious Is U0133, and Can You Drive?
The code alone cannot establish a safe driving distance. Follow the owner manual and vehicle warnings; stop safely and arrange qualified diagnosis if the affected function is abnormal.
Record warning messages, operating conditions and service history. Do not induce wheel slip, emergency braking or a handling event on public roads. A red stop warning or abnormal control overrides any verification plan.
Stop and arrange a tow if a safety-related function or the affected system behaves abnormally.
Follow the vehicle-specific electrical, steering, suspension or driveline safety precautions. Do not bypass interlocks or command powered safety components outside the approved procedure.
How to Diagnose U0133 in the Right Order
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Identify the reporting and named modules
Save full-system codes, active-roll warnings, status and operating context before clearing.
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Preserve the application and status evidence
Confirm the VIN-specific active-roll controller and separate it from suspension and steering modules.
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Inspect only the proven network branch
Inspect the approved power, ground, wake, connector and network branch without commanding restricted hardware casually.
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Separate communication from system performance
Compare the module’s access and current handling warnings; do not induce roll or slip to test the code on public roads.
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Choose repair only after external evidence
Apply the manufacturer diagnostic sequence to distinguish wiring, gateway, setup and controller branches.
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Verify the affected function and network state
Verify active-roll, suspension and stability functions as required by the OEM procedure.
Specifications are vehicle-specific. Use the exact VIN specifications, approved test points and required operating state. No generic value or drive cycle can replace the applicable procedure. Manufacturer examples here do not establish specifications for other applications.
U0133 Repairs and Cost Planning
A U0133 repair must address the demonstrated failure. Do not replace an assembly from the code alone.
Recheck installation and required setup after repair. No universal active-roll pressure, position, resistance or bus value is supplied by the code table.
Ask the shop to name the failed branch and the measurement supporting each proposed repair.
Authorize diagnosis before parts while the cause remains uncertain.
| Possible path | Quote basis |
|---|---|
| Repair the demonstrated power, ground, connector, harness, gateway or network branch | VIN-specific quote |
| Restore configuration, software or required setup only through the VIN-specific procedure | VIN-specific quote |
| Replace the isolated controller or assembly only after external evidence and the OEM test support that path | VIN-specific quote |
These are alternative repair paths, not prices to add together. Request a VIN-specific quote separating diagnosis, parts, labor, fluids, taxes, required setup and verification. Ask which failed test supports the proposed repair and whether warranty coverage applies.
Using iCarsoft CR Pro S for U0133
On a supported vehicle, iCarsoft CR Pro S can save accessible faults, available freeze frame, live data and diagnostic reports. Preserve the U0133 evidence before clearing.
Compare the saved and final module records. Scan data supports diagnosis but does not replace the OEM reference, physical measurement or safety-system functional check.
Preserve the active-roll control module evidence
iCarsoft CR Pro S
Review supported codes and relevant live data together. Confirm the exact VIN, controller access, PIDs and any requested active test with iCarsoft before purchase; generic product capabilities do not guarantee a U0133-specific function.
Check current CR Pro S price and availabilityCheck CR Pro S compatibility by VINThe official product page describes supported full-system diagnostics, available live data, freeze frame and diagnostic reports; exact controller coverage and active tests depend on the VIN and software. Confirm the requested function by VIN before purchase. Follow OEM prerequisites and stop for abnormal operation.
Know the measurement boundary. Scan data describes ECU-provided information; it does not directly prove the physical condition of the active-roll control module. Where required, use approved multi-module scan access, wiring diagram, voltage-drop/continuity tools and the VIN-specific network procedure and compare reported values with the relevant measured evidence.
Verify the U0133 Repair
After repair, verify installation, clearance and required setup. Save the final findings and clear only erasable records as instructed. Battery disconnection is not a repair.
Run the manufacturer's applicable verification conditions in a safe workshop or route. Compare the original operating state with current data for the active-roll control module, and check current and pending faults in related modules. A clean start or idle period does not prove the repair; use the OEM functional check for the affected system.
Compare the original and final fault status. Record the functional-check result and whether the original event returned.
If U0133 returns, compare its suffix, status, failure order and operating conditions with the saved baseline before replacing another part. Revisit the failed branch and inspect anything disturbed. Confirm the prescribed affected-system functional verification separately from code clearing.
Verification follows the system involved. After saving the original evidence, use the OEM procedure to clear erasable records, complete any required calibration or functional check, and compare the final module status with the original warning and fault conditions.
Related Active-Roll Control Module Code Guides
Compare the related monitor families below. Shared symptoms or components do not make their repair procedures interchangeable.
U0133 Frequently Asked Questions
Does U0133 prove the named module is bad?
No. The Autel table provides the code label only. Prove the VIN-specific supply, ground, connector, network and controller evidence before replacing a part; a clear scan does not prove the affected system is ready.
What should I check first for U0133?
Save every module's codes and freeze frame before clearing. Confirm the full definition, suffix and VIN architecture. Then inspect recent battery, interior, module, harness or software work, connectors and shared supplies. Those facts determine whether the next test needs approved multi-module scan access, wiring diagram, voltage-drop/continuity tools and the VIN-specific network procedure or a manufacturer-specific functional procedure.
Can I drive with the U0133 code?
The code alone cannot establish a safe driving distance. Follow the owner manual and vehicle warnings; stop safely and arrange qualified diagnosis if the affected function is abnormal.
Why did U0133 return after a part was replaced?
Compare the new record with the original suffix, reporting module and operating state. A replacement may leave an external message-path fault, installation issue or required setup unresolved. Reopen the failed diagnostic branch instead of treating the returning code as proof that the new part is defective.
What should a U0133 repair estimate include?
Ask for the failed-test evidence and a VIN-specific breakdown of diagnosis, parts, labor, taxes, required setup and verification. A code alone cannot establish the repair price.
Can CR Pro S diagnose and clear U0133?
On a supported vehicle, CR Pro S can organize available faults, freeze frame, live data and reports, and can clear erasable records after repair. Confirm exact ECU coverage. It cannot replace the OEM functional procedure or physical measurements for the active-roll control module.
The iCarsoft Official Store Technical Team maintains the store's fault-code library. This guide organizes published technical references and verified product information; it does not document a hands-on test of a particular vehicle or claim an individual engineer's review.
Technical and cost references
- Autel AL519 Diagnostic Trouble Code Definitions. Official code terminology, PDF p.99, exact U0133 entry; no vehicle-specific repair procedure.
- GM PIT5755 — module and bus mapping example. Manufacturer network context illustrating why module identity and application scope must be confirmed; not a universal U0133 procedure.
- Subaru Electrical Systems Operation & Diagnosis Module 602. General CAN no-message and safety context; not a U0133 wiring or threshold source.
Product information: Official iCarsoft CR Pro S page.
Editorial note: General diagnostic education, not a substitute for the owner's manual, current VIN-specific service information or professional inspection. Test limits, procedures, coverage and costs vary. Related articles provide context; apply only the specifications and repair procedures that match the vehicle. No universal failure rate, repair price or outcome is implied.
