U011A Code: Meaning, Symptoms, Causes & Fix

U011A

Overview

Code U011A indicates a fault in Lost Communication With Exhaust Gas Sensor Module, typically within module-to-module CAN communication.

Symptoms

  • module not responding in scan tool
  • intermittent no-start or limp mode
  • multiple warning lights at once

Common causes

  • Network termination or gateway fault affecting lost communication with exhaust gas sensor module
  • CAN bus wiring fault
  • Connector pin damage/corrosion or harness stress near related components

How to diagnose U011A

  1. Confirm U011A and capture freeze-frame data with a professional scan tool.
  2. Inspect wiring, connectors, and grounds related to lost communication with exhaust gas sensor module for obvious defects.
  3. Check CAN high/low integrity, network termination resistance, and module wake-up status.
  4. Check for related DTCs to identify the root-cause chain before replacing parts.
  5. After repair, clear codes and confirm readiness monitors complete without recurrence.

Severity of code U011A

Moderate: This code is moderate severity: the vehicle may still operate, but fault progression can increase repair cost over time.

Can you drive with U011A?

Most vehicles can be driven short-term with U011A, but postpone heavy load/highway driving until repaired.

If the warning lamp is flashing or drivability/safety is affected, avoid driving and diagnose immediately.

How to fix it (step-by-step)

  1. Repair obvious wiring/connector faults first to prevent repeat parts replacement.
  2. Address the root fault mode (communication) in the lost communication with exhaust gas sensor module circuit/system.
  3. Apply the required relearn/adaptation procedure if specified by service information.
  4. Road-test and verify U011A remains cleared under the conditions that originally set the code.

Fix options

  • Repair CAN high/low wiring or termination issue.
  • Scan all modules for communication chain faults.
  • Clear DTCs and verify with live data and completed drive cycle.

Typical repair cost

$260-$1300

Common mistakes when diagnosing U011A

  • Replacing parts without verifying voltage, ground, and signal integrity first.
  • Ignoring related stored/pending codes that indicate upstream faults.
  • Skipping post-repair verification drive cycle and readiness checks.

U011A in common vehicles

U011A appears across makes such as Ford, Toyota, Honda, Chevrolet. Failure patterns differ by platform: wiring routes, software calibration, and component supplier revisions can change root cause.

Frequently asked questions

What causes U011A?

U011A is commonly set by communication faults affecting lost communication with exhaust gas sensor module.

How much does it cost to fix U011A?

For U011A, repair costs are typically $260-$1300 depending on exact root cause, labor rates, and part quality.

Can I clear U011A without repair?

You can clear U011A temporarily, but the code usually returns until the underlying fault is corrected.

Helpful tools