What is the P0299 Code? Meanings, Causes and How Do You Fix Them

You might scan your vehicle with an OBDII scanner if your car has lost power. How do you respond to the P0299 message? The DTC indicates that the supercharger or turbocharger is at fault, although there could be other causes.

This guide will explain the P0299 code. This guide will also address the symptoms, causes and how to resolve the problem. 

Codification

P0299 – Turbocharger/Supercharger A Underboost Condition

What is the P0299 Code?

P0299 indicates that either the turbocharger or supercharger “A” shows an excessively low output. When the ECU detects a lower boost than what’s considered in the normal range, it will set the P0299 DTC. This code causes the Check Engine Light to come on, indicating that there’s a problem. 

The air flowing to the turbo- or supercharger's motor will be pressurized when it is normal operation. It’s how the engine can output more power for its size. However, when this code sets, the air can’t be pressurized the way it should be. 

Turbochargers make use of the exhaust gases coming from the engine. They also have a turbine which forces the air back into the intake. Superchargers, on the other hand work from the intake and are belt driven, forcing more air to the motor. 

P0299 Trouble code symptoms

The Check Engine Light will turn on when the trouble code P0299 is set. In order to prevent engine damage, the car could also switch into limp mode. You should be able to get home in the amount of time that you want without any additional problems.

These are some symptoms that you may notice.

What causes the P0299 code?

In general, you can expect that there’s a problem with the turbo, supercharger, or a boost pipe leak. But, other circumstances can cause the engine to produce less.

Some of the most frequent causes are:

• Turbo or supercharger defect
• A blocked or leaking air intake
• Leakage in the pipe lining
• Sensor for turbo-boost pressure is not functioning
• A malfunctioning wastegate or turbo pressure regulator
• EGR System fault (with turbo-set)
• Low oil pressure

Is the P0299 Code Really Severe?

Very high – The P0299 trouble code indicates some form of mechanical failure. If the car goes into limp mode to protect itself, you won’t be able to drive more than a short distance before repairing the problem.

Even if it doesn’t go into limp mode, you will probably notice some drivability issues, such as slow acceleration or loss of power. The car might make mechanical sounds, which should prompt you to have it checked out.

You could end up with more problems if you let a turbo or supercharger that isn't working continue to run. Permanent engine damage can follow, which isn’t cheap to fix. 

Which Repairs can Fix the P0299 Code

It’s impossible to determine what needs to be repaired to make the P0299 code disappear unless you complete a full diagnostic walkthrough. Although we may be able to give some suggestions about possible repairs, it isn't a substitute for a thorough examination.

Below are some possible repairs:

• Substitute supercharger
• Replace turbocharger
• Leakage repair on a boosted pipe
• Reparations to air intake
• Replace turbo boost pressure sensor (Or check & repair wirings)
• Replace boost pressure regulator/wastegate
• Repair low engine oil pressure
• Replacing EGR

Common mistakes in diagnosing P0299

Different car models may have different meanings for the P0299 DTC. The code might indicate a defective wastegate bypass valve in Volkswagen cars. Isuzu, on the other hand, uses this code to identify a stuck turbocharger solenoid control solenoid and low fuel pressure problems.

Ford is susceptible to a defective injector control pressure sensor. The VGT vanes could be sticking. You should ensure that you use the right diagnostics on your specific vehicle. 

Recommendations for Diagnosis

How to diagnose P0299 Trouble code

You can follow these steps to diagnose your vehicle just like a professional mechanic.

1. Check the problem codes with the scanner. It is possible to also fix any related codes if there are more than one.
2. You can view the data from the freezeframe to verify the codes were set.
3. To see if the car returns to normal, reset the codes.
4. You should inspect the boost pipes and let somebody rev the engine, while you look for whistling sounds that could be caused by a leak.
5. Visually inspect your turbocharger/supercharger. To determine if an issue is obvious, you should also inspect the EGR and the air intake systems.
6. If you are satisfied with the visual appearance, your scanner will allow you to read the readings of your boost pressure sensor. You can also rev the engine and try to regulate the boost pressure with the scan tool if it’s a good one.
7. Move the wastegate arm. If it’s stuck that could be the issue. If it’s a vacuum wastegate you can use a vacuum tool or air pressure tool to try to open and close it. The test can be more complicated if the turbocharger has an internal wastegate.
8. For leaks and blockages, inspect the air intake.
9. Verify the oil pressure. 

Calculated Cost for Repair

Here are some estimators to help you determine how much you will need to cover labor and parts to fix the problem.

• Replace supercharger – $2,500-$3,500
• Replace turbocharger – $1,500-$2,500
• Air intake repair – $250-$600
• Boost pipe leak repair – $0-$200
• Replace turbo boost pressure sensor – $150-$200
• Repair low engine oil pressure – $75-$250
• EGR valve replacement – $350-$500

The P0299 Code: Mechanics Tip

A turbo can fail, and a piece of turbine could be pulled into the engine. This doesn’t just create a severe loss of power, but it can also lead to loud mechanical noise. Additionally, it’s prone to ruin the engine, making this problem even more severe than when it started.