P2202 on Chevrolet
NOx Sensor Circuit Low Voltage (Bank 1, Sensor 1)
P2202 on Chevrolet vehicles indicates nox sensor circuit low voltage (bank 1, sensor 1). Au7o has documented this code across 1 Chevrolet model — most commonly on Silverado 2500HD. The PCM has detected that the signal voltage from the NOx (nitrogen oxide) sensor on Bank 1, Sensor 1 is lower than the expected operating range. The NOx sensor measures nitrogen-oxide content in the exhaust to manage the aftertreatment system (SCR/DEF on diesels or lean-burn emission control), so a low-voltage fault means the engine controller can no longer trust that reading. This is primarily a diesel and lean-burn emissions code and typically triggers reduced-emissions or limp-mode behavior. Typical repair costs on Chevrolet range from $400 to $1,400, depending on the specific model and root cause.
Common Causes of P2202
- •Failed or contaminated NOx sensor element (Bank 1, Sensor 1)
- •Short to ground or low resistance in the NOx sensor signal or supply wiring
- •Corroded, loose, or damaged sensor connector / pins
- •Open or high-resistance ground or reference circuit causing low signal
- •Exhaust leak or soot/sulfur contamination affecting the sensor
- •Faulty NOx sensor control module or PCM/ECM (less common)
P2202 on Chevrolet by Model
Chevrolet Silverado 2500HD(1 issue)
- LML Duramax NOx Sensor Drift - False 'DEF Quality Poor' Warning and Speed Limiter Countdown2011-2015
Early LML trucks (roughly 2011 through 2014) are documented for upstream and downstream NOx sensors that drift out of calibration rather than fail outright. The SCR system compares the two sensors to judge DEF effectiveness; when a sensor reads out of range the truck posts 'DEF Quality Poor' or 'Exhaust Fluid System - See Dealer' and begins a countdown that ultimately limits the truck to a 4 mph creep speed - with perfectly good DEF in the tank. Because the sensors drift in and out of range, the message often comes and goes, which is why owners replace sensors and see the light return. GM has published harness-chafe bulletins covering the same fault codes, so the wiring is a genuine root cause and not just a sensor problem.
Looking for P2202 on a different make?
View P2202 across all makes →Frequently Asked Questions
What does P2202 mean on Chevrolet?▼
P2202 stands for "NOx Sensor Circuit Low Voltage (Bank 1, Sensor 1)." The PCM has detected that the signal voltage from the NOx (nitrogen oxide) sensor on Bank 1, Sensor 1 is lower than the expected operating range. The NOx sensor measures nitrogen-oxide content in the exhaust to manage the aftertreatment system (SCR/DEF on diesels or lean-burn emission control), so a low-voltage fault means the engine controller can no longer trust that reading. This is primarily a diesel and lean-burn emissions code and typically triggers reduced-emissions or limp-mode behavior. On Chevrolet specifically, this code is documented across 1 model.
What causes P2202 on Chevrolet vehicles?▼
Common causes on Chevrolet: Failed or contaminated NOx sensor element (Bank 1, Sensor 1), Short to ground or low resistance in the NOx sensor signal or supply wiring, Corroded, loose, or damaged sensor connector / pins, Open or high-resistance ground or reference circuit causing low signal, Exhaust leak or soot/sulfur contamination affecting the sensor. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P2202 on a Chevrolet?▼
Repair costs on Chevrolet range from $400 to $1,400, depending on the specific model and root cause.
Which Chevrolet models have P2202 documented?▼
Au7o has documented P2202 on 1 Chevrolet model: Silverado 2500HD.