30E2
Low30E2 — NOx Sensor Fault During Thrust Test
Description
What the Code Means
Code 30E2 points to a fault detected during the thrust test of the NOx sensor. This test runs in forced overrun to check the sensor's response. The error sets when the NOx sensor's reaction to the change in exhaust composition during deceleration doesn't match what's expected. The NOx sensor measures nitrogen oxide concentration in the exhaust, and the engine management system uses that reading to fine-tune fuel delivery and EGR/SCR operation.
Symptoms
Symptoms
- Check Engine light is on
- Possible delayed throttle response or rough running during transient conditions
Causes and fixes
Diagnosis and Repair
Step 1
Run the thrust test with INPA diagnostic software. This checks the NOx sensor's dynamic response.
Step 2
Check the NOx sensor offset in static mode. Compare the reading against the reference values for this engine model.
Step 3
If the test fails and the offset is out of tolerance, replace the NOx sensor with a new OEM part or a quality equivalent.
Possible secondary damage
Secondary Problems
Ignoring the fault can lead to an incorrect fuel cut-off strategy during deceleration. That can cause higher fuel consumption, rough running during transient conditions, and increased NOx emissions. Over the long term, the catalytic converter or the EGR/SCR systems can fail from incorrect reagent dosing.