P0299 on RAM: How to Diagnose & Fix
Turbo/Supercharger Underboost Condition
1 RAM model · 1 documented issue · $200-$4,000 repair
P0299 on RAM by model: symptoms, diagnosis and fix
The RAM 3500 6.7L Cummins equipped with the integrated exhaust brake system experiences failures of the VGT (Variable Geometry Turbocharger) actuator and exhaust brake solenoid. The exhaust brake uses the VGT turbo vanes to create backpressure for engine braking while towing. The electronic actuator (Holset HE351VE/HE300VG) sticks or fails due to carbon buildup, causing loss of exhaust brake function, reduced turbo performance, limp mode, and DTC codes P2263 or P006A. TSB 14-001-21 addresses VGT actuator calibration. Actuator replacement costs $800-1,500; complete turbo replacement is $2,500-4,000.
Common Symptoms
- Exhaust brake not engaging or weak braking effect
- Check engine light with turbo codes (P2263, P006A, P0299)
- Reduced engine power / limp mode
- Black smoke from exhaust under acceleration
- Turbo whistle or surge at idle
- Slow turbo spool-up / turbo lag
- Exhaust brake light blinking
How to Fix
For sticking actuator: Remove and clean the VGT actuator and turbo vanes of carbon deposits. Actuator exercise procedure via wiTECH can help prevent sticking. Check TSB 14-001-21 for actuator calibration procedure. If the actuator motor is failed, replace the electronic actuator assembly ($800-1,500, Holset 5497296 or 5610723). If turbo vanes are severely carboned or damaged, complete turbo replacement is needed ($2,500-4,000). Regular highway driving helps keep vanes clean; trucks that idle excessively build up carbon faster.
P0299 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0299 mean on a RAM?
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 RAM it is documented across 1 model: 3500.
What are the most common causes of P0299?
The most common causes of P0299 are: 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. The specific cause varies by vehicle.
How much does it cost to fix P0299 on a RAM?
Published repair estimates on RAM range from $200 to $4,000 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0299 on a different make?
View P0299 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.