OBD Guide

U029E

Lost Communication With NOx Sensor B

U029E is an OBD-II diagnostic trouble code meaning: Lost Communication With NOx Sensor B. Common causes: broken or damaged wires to nox b sensor, malfunction of the nox b sensor itself. Estimated repair cost: $56–278.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$56–278 (est.)

Symptoms

  • Check Engine Light Is On
  • Reduced engine power
  • Increased fuel consumption
  • Activation of emergency operation
  • Problems with passing inspection due to emissions

Causes

  • Broken or damaged wires to NOx B sensor
  • Malfunction of the NOx B sensor itself
  • Problems with sensor connectors
  • Engine ECU malfunction
  • Short circuit in the sensor circuit

How to Fix

  1. Check the integrity of the wiring harness to the NOx B sensor
  2. Inspect the sensor connectors for corrosion or damage.
  3. Check the power supply and ground of the sensor
  4. Test or replace NOx B sensor
  5. Check ECU software for updates

Related codes

Error U029E by Vehicle Brand

FAQ

What does the U029E code mean?

U029E is an OBD-II diagnostic trouble code that indicates: Lost Communication With NOx Sensor B

What causes a U029E error code?

The most common causes of U029E include: Broken or damaged wires to NOx B sensor; Malfunction of the NOx B sensor itself; Problems with sensor connectors; Engine ECU malfunction.

How do I fix a U029E diagnostic trouble code?

To fix U029E: Check the integrity of the wiring harness to the NOx B sensor. Inspect the sensor connectors for corrosion or damage.. Check the power supply and ground of the sensor. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U029E?

Yes, but get it checked soon

How much does it cost to fix U029E?

The estimated repair cost for U029E is $56–278. Actual cost depends on your vehicle, location, and labor rates.

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