Faulty NOx sensor with an internal electronics failure; Damaged or corroded wiring or connector at the NOx sensor; Open or shorted controller area network (CAN) bus wiring between the sensor and ECM; Low or degraded battery voltage causing communication glitches; Water intrusion into the sensor connector or control module; Aftermarket or incorrect NOx sensor installed previously; ECM software issue or internal fault (less common)

DTC codes / U05xx · Network communication / U059E

U059EInvalid Data Received From NOx Sensor A

Q: What does code U059E mean?

Invalid Data Received From NOx Sensor A. The engine control module (ECM) received a data message from the nitrogen oxide (NOx) sensor that it considers invalid, meaning the sensor's internal processor reported a fault or sent values outside the expected range. This is a communication fault, not a direct performance fault, so the ECM cannot trust the NOx sensor's readings and may disable certain emissions strategies.

The engine control module (ECM) received a data message from the nitrogen oxide (NOx) sensor that it considers invalid, meaning the sensor's internal processor reported a fault or sent values outside the expected range. This is a communication fault, not a direct performance fault, so the ECM cannot trust the NOx sensor's readings and may disable certain emissions strategies.

SystemNetwork

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaNetwork communication

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Reduced engine power or limp mode in some vehicles as a protective strategy
Poor fuel economy or increased diesel exhaust fluid (DEF) consumption
Failed emissions inspection due to readiness monitors not completing
In rare cases, rough running or hesitation if the ECM defaults to a rich or derated fuel strategy

Common causes, most likely first

Faulty NOx sensor with an internal electronics failure
Damaged or corroded wiring or connector at the NOx sensor
Open or shorted controller area network (CAN) bus wiring between the sensor and ECM
Low or degraded battery voltage causing communication glitches
Water intrusion into the sensor connector or control module
Aftermarket or incorrect NOx sensor installed previously
ECM software issue or internal fault (less common)

How to diagnose and fix it

Scan all modules for related communication and NOx sensor codes, and record freeze-frame data
Visually inspect the NOx sensor connector and wiring for corrosion, chafing, or loose pins
Check battery voltage and charging system output to rule out low-voltage communication errors
Perform a voltage drop test on the sensor's power and ground circuits
Check CAN bus resistance and signal integrity with an oscilloscope if communication faults persist
Verify sensor part number and software compatibility, then replace the NOx sensor if wiring and power are good
Clear codes and perform a drive cycle to confirm the repair and complete emissions monitors

What the NOx sensor message really means

U059E is a communication code, so replacing the sensor without checking the wiring and power supply often leads to a repeat failure.
A weak or failing battery can cause intermittent invalid data messages from the NOx sensor even when the sensor itself is healthy.
Some vehicles require a software update or sensor calibration after replacement, and skipping this step can set the code again.
The NOx sensor contains a small control module, so heat damage or water intrusion at the connector can corrupt its data without any visible sensor damage.
This code can be stored alongside diesel particulate filter (DPF) or selective catalytic reduction (SCR) codes, so diagnose the communication fault first before chasing emissions performance codes.

Can I keep driving with U059E?

The vehicle is generally safe to drive short distances to a repair shop, but avoid heavy loads or long trips because the ECM may be running a default emissions strategy that increases DEF consumption or reduces power. If the engine enters limp mode, have the vehicle towed rather than driven at speed.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.