P11DC on Opel
NOx Sensor 2 Current Performance (Bank 1 Sensor 2)
P11DC on Opel vehicles indicates nox sensor 2 current performance (bank 1 sensor 2). Au7o has documented this code across 1 Opel model — most commonly on Grandland. P11DC indicates the engine control module has detected a current/performance fault with the downstream Nitrogen Oxide (NOx) sensor (Sensor 2, Bank 1), part of the Selective Catalytic Reduction (SCR) emissions system. The NOx sensor module reports an out-of-range or implausible signal to the ECM over the serial data line for more than the calibrated time, and the ECM stores the code. It signals the post-catalyst NOx reading is unreliable, which can disrupt emissions control and DEF/SCR dosing on diesels. Typical repair costs on Opel range from $250 to $1,200, depending on the specific model and root cause.
Common Causes of P11DC
- •Failed or aged downstream NOx sensor (Sensor 2 / Bank 1 Sensor 2)
- •Damaged, corroded, or loose NOx sensor wiring, connector, or serial data line
- •Exhaust leak near the SCR catalyst or sensor location skewing readings
- •Contaminated or degraded SCR/DEF catalyst affecting NOx conversion
- •Engine performance/combustion issues (misfire, EGR fault) raising actual NOx
- •Faulty NOx sensor control module or ECM software fault
P11DC on Opel by Model
Opel Grandland(1 issue)
- Diesel SCR/AdBlue & NOx Sensor Emissions Fault with 'Starting Impossible' Limp Mode2017-2023
Diesel Grandland X models (1.5 BlueHDi/1.6 diesel with SCR after-treatment) frequently throw exhaust after-treatment faults. Owners see emissions warnings, reduced power/limp mode, and the countdown message 'Engine start prevented in XXX miles/km'. Common root causes are NOx sensor failure (range/performance faults), SCR system or AdBlue injector/pump faults, crystallised AdBlue, or poor-quality urea. If ignored, the car eventually refuses to start. Critical phase is commonly around 30,000-45,000 km.
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View P11DC across all makes →Frequently Asked Questions
What does P11DC mean on Opel?▼
P11DC stands for "NOx Sensor 2 Current Performance (Bank 1 Sensor 2)." P11DC indicates the engine control module has detected a current/performance fault with the downstream Nitrogen Oxide (NOx) sensor (Sensor 2, Bank 1), part of the Selective Catalytic Reduction (SCR) emissions system. The NOx sensor module reports an out-of-range or implausible signal to the ECM over the serial data line for more than the calibrated time, and the ECM stores the code. It signals the post-catalyst NOx reading is unreliable, which can disrupt emissions control and DEF/SCR dosing on diesels. On Opel specifically, this code is documented across 1 model.
What causes P11DC on Opel vehicles?▼
Common causes on Opel: Failed or aged downstream NOx sensor (Sensor 2 / Bank 1 Sensor 2), Damaged, corroded, or loose NOx sensor wiring, connector, or serial data line, Exhaust leak near the SCR catalyst or sensor location skewing readings, Contaminated or degraded SCR/DEF catalyst affecting NOx conversion, Engine performance/combustion issues (misfire, EGR fault) raising actual NOx. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P11DC on a Opel?▼
Repair costs on Opel range from $250 to $1,200, depending on the specific model and root cause.
Which Opel models have P11DC documented?▼
Au7o has documented P11DC on 1 Opel model: Grandland.