U0133 — Lost Communication With Active Roll Control Module

OBD2 code U0133 flags a problem with the vehicle network (CAN bus) communication (lost communication with active roll control module). Short, gentle driving to a shop is usually possible. Common culprits: corroded connectors, especially in wet areas, a faulty module pulling the bus down, water ingress in harness junctions.

vehicle network

Is it safe to drive?

Drive with caution Depends on what is affected. A single dead convenience module is fine to drive with; loss of communication with engine, braking or steering modules is not. If multiple critical systems drop out, do not drive.

How to diagnose with an OBD scanner

  1. Read the code and freeze frame Connect an OBD2 scanner, confirm U0133 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many U0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the vehicle network (CAN bus) communication for damage, corrosion, chafing or poor contact.
  4. Subsystem check Measure resistance between CAN-High and CAN-Low at the OBD port with power off — about 60 Ω is healthy.
  5. Subsystem check Scan all modules: the one that does not respond is either the culprit or downstream of the break.
  6. Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm U0133 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for U0133 (parts and labor, USD, independent shop rates): Repair CAN wiring or connectors: $100–$400; Replace the faulty control module: $300–$1,500; Remove interfering aftermarket device: $0–$150. Overall, fixing U0133 usually costs between $0 and $1,500. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

Will U0133 clear itself?

Sometimes U0133 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

Is it safe to drive with U0133?

Depends on what is affected. A single dead convenience module is fine to drive with; loss of communication with engine, braking or steering modules is not. If multiple critical systems drop out, do not drive.

How do I diagnose U0133 myself?

Start with a scan: confirm U0133, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the vehicle network (CAN bus) communication, and verify the suspect component against live data before buying parts.

What are the symptoms of U0133?

Drivers most often notice: intermittent loss of functions (gauges, windows, steering assist), random, hard-to-reproduce electrical glitches, modules intermittently not communicating with the scanner, no-start or intermittent starting in some cases.

How much does it cost to fix U0133?

Repair CAN wiring or connectors — $100–$400; Replace the faulty control module — $300–$1,500; Remove interfering aftermarket device — $0–$150. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

What does U0133 mean?

The engine control module sets U0133 when it detects a fault in the vehicle network (CAN bus) communication. In practical terms: lost communication with active roll control module. The code belongs to the vehicle network group of OBD2 codes.

To set U0133, the control module compares live readings of the vehicle network (CAN bus) communication against calibrated limits, usually over several drive cycles. Alongside the code it stores a freeze frame — a snapshot of rpm, load, coolant temperature and vehicle speed at the moment of failure. Reading that snapshot first saves diagnostic time.

Common symptoms of U0133

  • intermittent loss of functions (gauges, windows, steering assist)
  • random, hard-to-reproduce electrical glitches
  • modules intermittently not communicating with the scanner
  • no-start or intermittent starting in some cases
  • multiple warning lights on at once

What causes U0133?

  • a faulty module pulling the bus down
  • aftermarket equipment interfering with the bus
  • poor grounds or low battery voltage
  • damaged CAN bus wiring or short to power/ground
  • water ingress in harness junctions
  • corroded connectors, especially in wet areas

How to diagnose U0133

  1. Connect an OBD2 scanner, confirm U0133 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many U0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Visually inspect the wiring harness and connectors related to the vehicle network (CAN bus) communication for damage, corrosion, chafing or poor contact.
  4. Measure resistance between CAN-High and CAN-Low at the OBD port with power off — about 60 Ω is healthy.
  5. Scan all modules: the one that does not respond is either the culprit or downstream of the break.
  6. Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm U0133 does not return.

How to fix U0133

Start with the cheapest and most common causes before replacing expensive parts:

  • Repair CAN wiring or connectors — $100–$400
  • Replace the faulty control module — $300–$1,500
  • Remove interfering aftermarket device — $0–$150

How much does it cost to fix U0133?

Repair cost depends on which component actually failed. Typical scenarios for U0133 (parts and labor, USD, independent shop rates):

  • Repair CAN wiring or connectors: $100–$400
  • Replace the faulty control module: $300–$1,500
  • Remove interfering aftermarket device: $0–$150

Overall, fixing U0133 usually costs between $0 and $1,500. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Can you drive with U0133?

Depends on what is affected. A single dead convenience module is fine to drive with; loss of communication with engine, braking or steering modules is not. If multiple critical systems drop out, do not drive.

Related OBD2 codes