P11DB on 2018-2019 Chevrolet Equinox (LT, Premier) — NOx Sensor Current Performance Bank 1 Sensor 1
1 vehicles · 1 makes · $350-$1,500 repair
Most Reported On
P11DB is an OBD-II diagnostic trouble code meaning “NOx Sensor Current Performance Bank 1 Sensor 1.” A GM-specific code (commonly seen on Duramax diesel trucks and vans) covering the upstream NOx sensor in the selective catalytic reduction (SCR) aftertreatment system. The sensor's current draw is proportional to NOx concentration, and the ECM sets this code when it detects a circuit fault or a performance fault in that signal for more than about two seconds. Expect a check engine light; because the NOx reading meters DEF dosing, related aftertreatment faults on these trucks can escalate to a speed-limiting or power-reduction countdown if left unrepaired. This code is most commonly reported on 2018-2019 Chevrolet Equinox (LT, Premier), with repair costs ranging from $350 to $1,500.
Common Causes
Typical Repair Cost
Based on 1 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
P11DB does not use the standard P/B/C/U prefix. It may be a manufacturer-specific code, so verify that a scanner supports your exact year, model and module before buying.
FAQ
What does P11DB mean?
P11DB stands for "NOx Sensor Current Performance Bank 1 Sensor 1." A GM-specific code (commonly seen on Duramax diesel trucks and vans) covering the upstream NOx sensor in the selective catalytic reduction (SCR) aftertreatment system. The sensor's current draw is proportional to NOx concentration, and the ECM sets this code when it detects a circuit fault or a performance fault in that signal for more than about two seconds. Expect a check engine light; because the NOx reading meters DEF dosing, related aftertreatment faults on these trucks can escalate to a speed-limiting or power-reduction countdown if left unrepaired.
What are the most common causes of P11DB?
The most common causes of P11DB are: Failed upstream NOx sensor (bank 1, sensor 1) — the most common cause, Open, shorted, chafed, or corroded NOx sensor wiring harness, Poor electrical connection or water intrusion at the sensor connector, Exhaust leak upstream of the sensor skewing the reading, Contaminated DEF or a DEF dosing fault upsetting NOx values, Outdated ECM/aftertreatment control module calibration (check for applicable TSBs). The specific cause varies by vehicle.
How much does it cost to fix P11DB?
Repair costs for P11DB range from $350 to $1,500, depending on the vehicle and root cause.
Which vehicles are affected by P11DB?
Au7o has documented P11DB across 1 vehicle models from 1 manufacturers: Chevrolet.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.