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.
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 communications
2Original wording in English
HINO
Reported code forms P0299
SB-17-013 CHARGE AIR COOLER (CAC) INSPECTION P0299 P226C -- In the event that a subject vehicle exhibits low power with DTC (Diagnostic Trouble Code) P0299 (underboost) and/or P226C (boost pressure slow response),…
HINO
Reported code forms P0299
TT-15-026 Subject vehicles may exhibit a MIL lamp on with reduced engine power due to a restriction in the exhaust system such as a plugged DPF. The technician may find DTC?s (Diagnostic Trouble Codes) such as P244B,…
Check vehicle applicability
6A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
| Make | Model | Model year |
|---|---|---|
| Hino | CONVENTIONAL TRUCKS W/JO8 | 2016 |
| Hino | CONVENTIONAL TRUCKS W/JO8 | 2015 |
| Hino | CONVENTIONAL TRUCKS W/JO8 | 2014 |
| Hino | CONVENTIONAL TRUCKS W/JO8 | 2013 |
| Hino | CONVENTIONAL TRUCKS W/JO8 | 2012 |
| Hino | CONVENTIONAL TRUCKS W/JO8 | 2011 |
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.