What does this code mean?
The monitored boost is insufficient for the calibrated operating condition. This describes a control result, not proof of a failed turbocharger. Air-path restriction, control-system behavior and environmental conditions must be evaluated within the vehicle procedure. The cited GM bulletin documents an ice-related case with possible reduced power.
Sources and interpretation [1] [3]
A code identifies a detected condition, not a part that must automatically be replaced.
GM 22-NA-002 covers 2018–2022 Equinox/Terrain 1.5L LYX in the US/Canada and links cold-weather codes to moisture/ice and boost control. Its first-page list labels P0234 as underboost; that conflicts with the Ford/Audi overboost definition. We use it for the scoped cold-weather example, not to redefine P0234.
Sources and interpretation [2]
Before replacing a part
Record whether the fault occurs only in cold weather and compare desired with actual boost. Review the exact engine's air path and boost-control tests. A cold-weather bulletin is not evidence that every P0299 requires a turbocharger or software replacement.
Manufacturer wording
Source wording can vary by vehicle and suffix. It is shown as written, not as a universal diagnosis.
P0299-00Turbocharger UnderboostP0299Negative Pressure DeviationP0299-00Turbocharger Underboost ConditionP0299Turbocharger UnderboostView all · Manufacturer wording →
Manufacturer communications
285Original wording in English
AUDI
Reported code forms P0299
This Pending Service Solution (PSS) requests that technicians create a record in the PSS database when there is an exhaust emissions warning lamp illuminated, DTC P0299 sumptom 34203; V6 TFSI.
AUDI
Reported code forms P0299
This Pending Service Solution (PSS) requests that technicians create a record in the PSS database when there is an exhaust emissions warning lamp illuminated, DTC P0299 sumptom 34203; V6 TFSI.
AUDI
Reported code forms P0299
This Pending Service Solution (PSS) requests that technicians create a record in the PSS database when there is an exhaust emissions warning lamp illuminated, DTC P0299 sumptom 34203; V6 TFSI.
BUICK, CHEVROLET, GMC
Reported code forms P0299
This document assists dealer technician's with diagnosing a MIL P0299.
AUDI
Reported code forms P029900
This bulletin provides informaiton when DTC P029900 is stored in ECM - V6 TFSI EA839evo.
HINO
Reported code forms P0299
SB 26-004 2015-2020 MY COE CAC INLET HOSE Subject vehicles may experience a MIL (Malfunction Indicator Lamp) illuminated with one or more of the DTC’s (Diagnostic Trouble Codes) listed in the table below. Other symptoms…
Check vehicle applicability
800A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
| Make | Model | Model year |
|---|---|---|
| Alfa Romeo | GIULIA | 2020 |
| Alfa Romeo | GIULIA | 2019 |
| Alfa Romeo | GIULIA | 2018 |
| Alfa Romeo | GIULIA | 2017 |
| Alfa Romeo | STELVIO | 2020 |
| Alfa Romeo | STELVIO | 2019 |
| Alfa Romeo | STELVIO | 2018 |
| Audi | A3 | 2007 |
| Audi | A3 | 2006 |
| Audi | A3 | 2005 |
| Audi | A4 | 2014 |
| Audi | A4 | 2013 |
Sources and interpretation
These explanations are editorial summaries of the linked manufacturer material. PDF page numbers count from the first file page. Original publications are in English; translations are reference aids. A cited edition is not a claim that it is the manufacturer's latest instruction.
- Audi TT Quick Reference Specification Book · October 2013 ↗
Audi of America · PDF page(s) 137 ·
- 22-NA-002 · P0299/P0234 during cold or freezing temperatures ↗
General Motors · PDF page(s) 1 ·
- 2024–2025 MY OBD System Operation Summary for Gasoline Engines ↗
Ford Motor Company · PDF page(s) 86, 87 ·
Source check date · 2026-10-27
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.