P0299 on Buick
Turbo/Supercharger Underboost Condition
P0299 on Buick vehicles indicates turbo/supercharger underboost condition. Au7o has documented this code across 2 Buick models — most commonly on Encore, Encore GX. P0299 means the engine computer detected an underboost condition — the turbocharger or supercharger is producing less boost pressure than the PCM expects for the given conditions. The computer compares the manifold/boost pressure sensor reading to a target based on engine load, and when actual boost falls short, it sets this code. The most common real-world cause is a leak somewhere in the intake/charge-air path. You'll typically feel reduced power or sluggish acceleration, and the engine may go into a reduced-power mode.
Common Causes of P0299
- •Boost/intake leak (cracked or loose charge-air hose or intercooler)
- •Faulty or sticking turbo wastegate or actuator
- •Stuck or clogged variable-geometry turbo vanes (VGT)
- •Faulty boost pressure or MAP sensor
- •Leaking or disconnected vacuum/boost control lines
- •Restricted air intake or clogged air filter
- •Failed boost control solenoid
- •Worn or failing turbocharger
P0299 on Buick by Model
Buick Encore(3 issues)
- Turbocharger Can Fail (Special Coverage N232395330)2017-2018
GM Special Coverage N232395330 identifies certain 2017-2018 Buick Encore vehicles with the 1.4L LUV engine whose turbocharger can fail. The documented result is a check-engine light with a turbo-related DTC, rough engine operation or reduced power.
- Charge-Air Cooler Icing Can Cause Cold-Weather Power Loss (17-NA-221)2016-2018
GM Bulletin 17-NA-221 covers specified 2016-2018 Encore vehicles with the LE2 engine, through the September 18, 2017 build breakpoint. At 0°F (-18°C) or below, ice can accumulate in the charge-air cooler and restrict airflow, causing power loss, hesitation, stalling, tailpipe smoke, an oil odor or MIL during the first 10-15 minutes of operation.
- Oil Consumption, Blue Smoke or PCV Faults (PIP5197H)2013-2019
GM PIP5197H covers 2013-2019 Encore vehicles with the 1.4L LUJ/LUV engine. The documented concern includes oil use of at least one quart per 2,000 miles when not caused by an external leak, blue exhaust smoke, a whistle, MIL or fuel-trim codes. Possible causes include a leaking cam-cover PCV orifice, a missing intake-manifold non-return valve or a weak/broken piston ring land.
Buick Encore GX(1 issue)
- 1.2L Turbocharger Can Fail (2020-2022 Special Coverages)2020-2022
GM Special Coverages N232407740, N242450640 and N242484750 identify certain 2020, 2021 and 2022 Buick Encore GX vehicles with the 1.2L LIH engine whose turbocharger can fail. The documented signs are a check-engine light and diagnostic trouble code, a possible reduced-engine-power message, and commonly a cold-start rattle or P0299 during diagnosis.
Looking for P0299 on a different make?
View P0299 across all makes →Frequently Asked Questions
What does P0299 mean on Buick?▼
P0299 stands for "Turbo/Supercharger Underboost Condition." P0299 means the engine computer detected an underboost condition — the turbocharger or supercharger is producing less boost pressure than the PCM expects for the given conditions. The computer compares the manifold/boost pressure sensor reading to a target based on engine load, and when actual boost falls short, it sets this code. The most common real-world cause is a leak somewhere in the intake/charge-air path. You'll typically feel reduced power or sluggish acceleration, and the engine may go into a reduced-power mode. On Buick specifically, this code is documented across 2 models.
What causes P0299 on Buick vehicles?▼
Common causes on Buick: Boost/intake leak (cracked or loose charge-air hose or intercooler), Faulty or sticking turbo wastegate or actuator, Stuck or clogged variable-geometry turbo vanes (VGT), Faulty boost pressure or MAP sensor, Leaking or disconnected vacuum/boost control lines. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0299 on a Buick?▼
Repair costs vary widely depending on the root cause and specific Buick model.
Which Buick models have P0299 documented?▼
Au7o has documented P0299 on 2 Buick models: Encore, Encore GX.