Service Engine Soon Lamp (MIL) On with NOx Sensor Faults Stored. The Service Engine Soon lamp (MIL) is on with either of the following nitrogen oxide (NOx) sensor faults stored: * 2B6200 - NOx sensor before DeNOx catalytic converter, plausibility: Sensor self-diagnosis of sensitivity * 2B6300 - NOx sensor After DeNOx catalytic converter, plausibility: Sensor self-diagnosis of sensitivity These stored faults would not cause a problem with engine performance. This NOx self-diagnostic routine is performed only after the engine has been shut off. In some situations, the diagnostic function of both NOx sensors can be too sensitive when sampling the residual exhaust gases, leading to an erroneous fault being set. Unfavorable DDE software diagnostics
