OBD Guide

U12A3

Lost Communication With Particulate Matter Sensor

U12A3 is an OBD-II diagnostic trouble code meaning: Lost Communication With Particulate Matter Sensor. Common causes: broken or damaged wiring to the sensor, malfunction of the particle sensor itself. Estimated repair cost: $50–133.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$50–133 (est.)

Symptoms

  • Check Engine Light Is On
  • Possible reduction in engine power
  • The diesel particulate filter regeneration system may not work
  • The need for manual filter regeneration
  • Possible problems when passing technical inspection

Causes

  • Broken or damaged wiring to the sensor
  • Malfunction of the particle sensor itself
  • Problems with connection connectors
  • Engine ECU malfunction
  • Short circuit in the sensor circuit

How to Fix

  1. Check the integrity of the wiring harness to the sensor
  2. Inspect the sensor connectors for corrosion or damage.
  3. Check the power and ground of the sensor circuit
  4. Test the sensor using diagnostic equipment
  5. If necessary, replace the sensor or wiring

Related codes

FAQ

What does the U12A3 code mean?

U12A3 is an OBD-II diagnostic trouble code that indicates: Lost Communication With Particulate Matter Sensor

What causes a U12A3 error code?

The most common causes of U12A3 include: Broken or damaged wiring to the sensor; Malfunction of the particle sensor itself; Problems with connection connectors; Engine ECU malfunction.

How do I fix a U12A3 diagnostic trouble code?

To fix U12A3: Check the integrity of the wiring harness to the sensor. Inspect the sensor connectors for corrosion or damage.. Check the power and ground of the sensor circuit. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U12A3?

Limited driving only, diagnose soon

How much does it cost to fix U12A3?

The estimated repair cost for U12A3 is $50–133. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat