OBD Guide

U05A1

NOx Sensor A Received Invalid Data From ECM/PCM

U05A1 is an OBD-II diagnostic trouble code meaning: NOx Sensor A Received Invalid Data From ECM/PCM. Common causes: nox sensor malfunction, damage to the wiring to the nox sensor. Estimated repair cost: $167–444.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$167–444 (est.)

Symptoms

  • Increased fuel consumption
  • Check Engine Light Illuminates
  • Reduced engine power
  • Unpleasant exhaust smell
  • Possible transition to emergency mode

Causes

  • NOx sensor malfunction
  • Damage to the wiring to the NOx sensor
  • Problems with sensor connectors
  • Engine control unit malfunction
  • Software error in ECM/PCM

How to Fix

  1. Check the integrity of the wiring to the NOx sensor
  2. Inspect the sensor connectors for corrosion or damage.
  3. Check NOx sensor readings using a diagnostic scanner
  4. If necessary, replace the NOx sensor
  5. Update ECM/PCM software

Related codes

Error U05A1 by Vehicle Brand

FAQ

What does the U05A1 code mean?

U05A1 is an OBD-II diagnostic trouble code that indicates: NOx Sensor A Received Invalid Data From ECM/PCM

What causes a U05A1 error code?

The most common causes of U05A1 include: NOx sensor malfunction; Damage to the wiring to the NOx sensor; Problems with sensor connectors; Engine control unit malfunction.

How do I fix a U05A1 diagnostic trouble code?

To fix U05A1: Check the integrity of the wiring to the NOx sensor. Inspect the sensor connectors for corrosion or damage.. Check NOx sensor readings using a diagnostic scanner. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U05A1?

Yes, but get it checked soon

How much does it cost to fix U05A1?

The estimated repair cost for U05A1 is $167–444. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat