U029D

Lost Communication With NOx Sensor A

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$167–444 (est.)

Symptoms

Check Engine light comes on
Reduced engine power
Increased fuel consumption
Problems with passing environmental tests
Possible SCR system error messages

Causes

NOx sensor A fault
Open or short circuit in the sensor circuit
Damaged or oxidized connectors
Sensor power problems
Engine control unit malfunction

How to Fix

Check the integrity of the NOx sensor wiring and connectors
Check the power supply and ground of the sensor
Read sensor parameters via diagnostic scanner
If necessary, replace NOx sensor A
Check and update ECU software if necessary

Related codes

U029E P2200 P2201