OBD Guide

U02A1

Lost Communication With NOx Sensor C

U02A1 is an OBD-II diagnostic trouble code meaning: Lost Communication With NOx Sensor C. Common causes: open or short circuit in the nox sensor circuit, malfunction of the nox 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 comes on
  • Reduced engine power
  • Increased fuel consumption
  • Unstable engine idling
  • Possible transition to emergency mode

Causes

  • Open or short circuit in the NOx sensor circuit
  • Malfunction of the NOx sensor itself
  • Connector problems or contact corrosion
  • ECU malfunction
  • Wiring harness damage

How to Fix

  1. Check the continuity of the NOx sensor circuit
  2. Inspect the connectors and contacts of the sensor for damage
  3. Check the power supply and ground of the sensor
  4. Replace NOx sensor if necessary
  5. Check and update the ECU firmware

Related codes

Error U02A1 by Vehicle Brand

FAQ

What does the U02A1 code mean?

U02A1 is an OBD-II diagnostic trouble code that indicates: Lost Communication With NOx Sensor C

What causes a U02A1 error code?

The most common causes of U02A1 include: Open or short circuit in the NOx sensor circuit; Malfunction of the NOx sensor itself; Connector problems or contact corrosion; ECU malfunction.

How do I fix a U02A1 diagnostic trouble code?

To fix U02A1: Check the continuity of the NOx sensor circuit. Inspect the connectors and contacts of the sensor for 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 U02A1?

Yes, but get it checked soon

How much does it cost to fix U02A1?

The estimated repair cost for U02A1 is $56–278. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat