2BA100
Moderate2BA100 — NOx Sensor Circuit Open After SCR
Description
What Code 2BA100 Means
Code 2BA100 points to an open circuit in the NOx sensor located downstream of the SCR system (Selective Catalytic Reduction). The fault is intermittent — the circuit opens periodically rather than staying open.
The NOx sensor monitors how well the SCR system reduces nitrogen oxide emissions. With an open circuit, the sensor can't send a correct signal to the engine control unit (DME), so emissions readings come back wrong. The SCR system works alongside the diesel particulate filter (DPF), and losing NOx feedback can affect regeneration strategy and the catalytic conversion efficiency diagnostics.
Symptoms
Symptoms
- Warning light: the Check Engine light may come on.
- Diesel particulate filter: heavy DPF clogging is possible from incorrect regeneration cycles.
- Emissions: higher emissions are likely.
- Engine operation: the engine may drop into limp mode.
Causes and fixes
Diagnosis and Repair
Check the NOx Sensor Circuit
- Inspect the wiring and connector of the NOx sensor after the SCR for damage and corrosion.
- Confirm there's no open circuit and that the contact is solid.
Replace the Sensor
- If the sensor is faulty, replace it.
Check the SCR System and DPF
- Verify the SCR system is working.
- A DPF that's excessively clogged can create backpressure problems, so check for that too.