P0299 on Jeep
Turbo/Supercharger Underboost Condition
P0299 on Jeep vehicles indicates turbo/supercharger underboost condition. Au7o has documented this code across 2 Jeep models — most commonly on Grand Cherokee, Liberty. 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. Typical repair costs on Jeep range from $500 to $3,000, depending on the specific model and root cause.
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 Jeep by Model
Jeep Grand Cherokee(1 issue)
- 2014-2019 Grand Cherokee EcoDiesel EGR Cooler Fire-Risk Recall (W79 / 20V-699)2014-2019
Certain 2014-2019 Jeep Grand Cherokee vehicles with the 3.0L EcoDiesel engine are included in safety recall W79 / NHTSA 20V-699. NHTSA lists 28,884 potentially involved Jeep vehicles. Thermal fatigue can cause the EGR cooler to crack internally over time, allowing pre-heated vaporized coolant into the EGR system; under some conditions the mixture can combust inside the intake manifold and lead to a vehicle fire. Recall inclusion is VIN-specific. The prior card overstated the Jeep population as 34,334, attached unsupported generic EGR codes, and offered OEM, aftermarket, manifold, and gasket purchases even though the recall repair is free and inspection-dependent.
Jeep Liberty(1 issue)
- 2.8L CRD Diesel - EGR Valve Failure Causing Boost Spikes and Turbocharger Damage2005-2006
The KJ-only 2.8L VM Motori CRD diesel (2005-2006 North America) uses an EGR valve that also acts as a pressure relief path for the turbocharger under certain conditions. When the valve carbons up and sticks - the standard outcome given the oily EGR fume load in the intake - boost pressure is no longer relieved and can spike hard enough to damage the turbo. Owners document the whole chain: heavy soot in the intake, rotted intake hose at the turbo from oily fumes, stalling, hesitation, smoke, long turbo lag (one owner measured roughly 2 seconds of lag that dropped to about half a second after EGR replacement), and eventually turbo failure with P0299 underboost. Chrysler changed EGR suppliers near the end of the 2005 production run and fitted the newer-style valve to earlier CRDs under warranty; all 2006 units received the later valve. This is a diesel-only failure and does not apply to the 3.7L V6.
Looking for P0299 on a different make?
View P0299 across all makes →Frequently Asked Questions
What does P0299 mean on Jeep?▼
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 Jeep specifically, this code is documented across 2 models.
What causes P0299 on Jeep vehicles?▼
Common causes on Jeep: 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 Jeep?▼
Repair costs on Jeep range from $500 to $3,000, depending on the specific model and root cause.
Which Jeep models have P0299 documented?▼
Au7o has documented P0299 on 2 Jeep models: Grand Cherokee, Liberty.