Encore P0299 in extreme cold: GM’s LUV and LE2 corrections
The short answer
P0299P0299 means “Engine Underboost” in GM’s code list: the engine is producing less boost than expected.
On the listed Encore engines, ice can restrict the charge-air system and disturb boost control. GM uses separate LUV and LE2 correction packages. Both require a matched engine and a confirmed cold-weather condition; the LUV path also addresses the PCV bypass system.
| Model year | Model | Engine RPO | GM bulletin / pages | Revision |
|---|---|---|---|---|
| 2013–2021 | Encore | 1.4L LUV | 16-NA-405 · PDF 1–3 | 2023-05 |
| 2016–2019 and 2021–2022 | Encore | 1.4L LE2 | 17-NA-221 · PDF 1–2 | 2022-06 |
Does this reference cover your vehicle?
- Model year
- 2013–2021
- Model
- Encore
- Engine RPO
- 1.4L LUV
- GM bulletin / pages
- 16-NA-405 · PDF 1–3
- Revision
- 2023-05
- Note
- —
- Model year
- 2016–2019 and 2021–2022
- Model
- Encore
- Engine RPO
- 1.4L LE2
- GM bulletin / pages
- 17-NA-221 · PDF 1–2
- Revision
- 2022-06
- Note
- —
In this guide
The pattern that makes icing relevant
The bulletins describe extreme cold at 0°F (−18°C) or below. The LE2 document adds short or slow driving with symptoms in the first 10–15 minutes. For the LUV, GM places the system-leak check first for P0299; moisture by itself is a poor indicator of actual freezing.
The LE2 bulletin accounts for the 2020 gap: the LE2 engine was absent from this application in model year 2020. Confirm the engine by its RPO and leave the table’s gap as published.
Source: 16-NA-405 · PDF 1 · 17-NA-221 · PDF 1
LUV: check which cold-weather components are already fitted
16-NA-405 covers icing in the PCV bypass, intake passages and charge-air cooler. After the condition is confirmed, the service path checks the winter cover, heated PCV bypass system, revised cooler and outlet elbow duct. The correction depends on what is already installed and what the inspection finds.
GM limits the PCV-heater parts to the specified extreme-cold regions and conditions. A winter cover must be removed when temperatures stay above 32°F (0°C) and before towing. These are application limits for the workshop’s selection of the package.
Source: 16-NA-405 · PDF 2
LE2: thawing, cooler/control checks and selected calibration
17-NA-221 calls for thawing before service and cooler replacement when the relevant symptoms are verified as icing-related. It also addresses moisture in the turbocharger control valve (TCV), with inspection directed by the codes.
The new ECM calibration described there applies only to LE2 model years 2018, 2019 and 2021. The update changes cold-weather shifting to use overdrive less often, so highway engine speed can be higher. The shop should explain that expected change when it performs the update.
Source: 17-NA-221 · PDF 2
The useful record
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Record the temperature, time since start and whether power returns later in the trip. With that record, the shop can match the engine, establish the cause and check the car’s update history. The code definition comes from GM’s 22-NA-224 list; its Malibu repair path is outside this Encore guide.
Source: 16-NA-405 · PDF 1 · 17-NA-221 · PDF 1