How to Fix the P0046 Code on Duramax (Proficient Solutions)

Duramax car engines are turbocharged or supercharged to perform better. The PCM maintains the turbo/supercharge or VGT system in the vehicle. It controls the pressure and fuel consumption rate to make the air induction function smooth. 

If you see the DTC code P0046 in your car monitor, it means the turbocharger or supercharger boost control circuit of your duramax lacks performance. In other words, when the boost control or the control circuit gets corrupted or disconnected and causes a performance drop, this code blinks on the car screen. 

Basically, improper boost regulation causes the P0046 code on the car. Now, let’s see when and why this issue arises. Also, we’re telling you how to deal with this problem with the reasons. 

How to Fix the P0046 Code on Duramax

What Does Code P0046 Mean On Duramax?

To control the boost, air pump, and pressure, the PCM (Powertrain Control Module) uses a wastegate valve or solenoid. But in some modern cars with a VGT system, the solenoid shifts or changes turbine blade speed to regulate the boost amount and pressure.

In traditional or modern structures, the necessary regulation is performed by the PCM via the key solenoid or motor. Apart from that, there are some strong sensors attached to the boost unit to monitor the performance and RPM shifts. 

Whenever an engine’s boost system shows unusual behavior for some reason, and it is causing the vehicle to perform less than before, you can see P0046 on the screen. 

In other words, P0046 means any of the circuits or components have failed to work accordingly. If we elaborate on the code characters, we find:

  • P = Powertrain, the specific electric system in the automobile
  • 0 = OBD II standard
  • 0 = Fuel and air metering, a subset of errors
  • 46 = Turbo/Supercharger boost control circuit range performance, specified issue

How Serious Is Code P0046 On Duramax?

As the boost system is directly linked with the engine, you can put your car engine into trouble by driving after the code appears. The car can suffer from a huge amount of power loss because of the P0046 issue. 

Basically, a boost system is integrated with a small Duramax engine to work like a heavy utility vehicle engine. When the turbo/supercharge functions badly, you’d find a lack of power in the acceleration. Which actually puts pressure on the engine that needs to work like before without the help of the boost system. 

But the issue becomes bigger if the solenoid or wastegate of the turbo or super is somehow damaged. Due to a lack of regulation, the engine gets overboosted and works beyond its capacity. Whether it’s underboost or overboost, the engine suffers the direct effects of it. 

What Causes Code P0046 On Duramax?

The most common reason for your car showing P0046 is a Faulty Boost pressure sensor. Besides, you can also see the code because of software bugs. Here’s the list of stuff that’d cause p0046 in a Duramax engine. 

  • Bad boost pressure or position sensor
  • Leakages in the vacuum
  • Damaged turbo/super charger
  • Loose, burnt, or shortened wires from the circuits and sensors
  • Temperature rise in the engine
  • Worn-out solenoid or wastegate
  • Broken blades
  • Black smoke
  • Oil leakage
  • PCM malfunction

How To Fix Code P0046 On Duramax?

It takes more than a couple of hours and some scanners to properly diagnose and troubleshoot the code P0046 of Duramax engines. Let’s see how an expert would fix the code. 

Step 1: Check the code’s validity

Note down all the logged codes on the screen and reset the computer. If the code doesn’t show up on the test drive after the reset, consider the code invalid. 

Step 2:  Look for any loose wiring or damaged cables

If the code still shows up, then you must run a deep check. First, make sure the wires are perfectly connected at the right spots. And you must replace any short or burnt wires to make the boost system work properly. 

Step 3: Inspect the turbine, intake hose, and pipes to find any leakage or damage

Then, check out the turbine blades, intake hoses, and other piping to find any possible leakage or damage. A leakage can let oil corrupt the turbine or release the necessary pressure. 

Step 4: Crosscheck the system’s function with an RPM test

Now, take a bi-directional scan tool and change the position of the solenoid. After that, shift the engine RPM around 1200-1250. Meanwhile, turn the solenoid on and off. By this, you can see the RPM rate changing along with the PID position change in the scanner. 

  • But if only the RPM changes, the sensor system should need a fix or replacement. 
  • And when there’s no RPM change, consider the solenoid or the turbo/super charger is at fault. You might also need to change the booster. 

Step 5: Test the PCM and other stuff

It is not very unusual for the PCM to show p0046 even when the boost system is okay. In that case, you must ensure the PCM is working without any bugs. The battery is providing enough power, and there’s no oil leakage. By ensuring all of these, you can make your Duramax engine work as before. 

Other Symptoms of Getting a P0046 Code on Duramax

The main symptom of having P0046 in your Duramax engine is a performance drop. There are some other noticeable things that can happen in the engine. It’s better to know all the common symptoms of getting p0046 so that you can troubleshoot with ease.

  • Check Engine Light turned on
  • Poor mileage
  • Unusual behavior from the combustion chamber
  • Engine Detonation
  • Hard to accelerate 
  • Power loss

How Much Does It Cost To Fix The Duramax P0046 Code?

If you hire a mechanic or visit the dealership nearby, you will need to spend around 100-150$ for the labor cost only. You can save the amount if you know how to diagnose and deal with such stuff by yourself. 

However, there’s one more thing. Most of the time, the solution to P0046 is to replace a component of the turbo/supercharger or the whole boosting system. Replacing a booster or sensor won’t be cheap. Even a small sensor would cost around $200-$400. And a new VGT or turbo boost can be found in the $1000-$1800 range depending on your car model. 

So, you must consider the price of OEM parts if you need to replace the old ones. Also, you need to count the fees of an expert for replacing the boost system if you don’t know the DIY process. 

Can You Drive Your Duramax with a P0046 Code?

The straight answer is no. Duramax engines with boost systems only work well when the turbo/supercharger increases capacity and performance. The missing support from boosting can raise tension in the engine. Very soon, your engine will be permanently damaged if you don’t fix the turbo/supercharger boost or VGT. 

You must stop using your car and take it to your garage or nearby auto shop when you see the engine light blinking with P0046 logged. Otherwise, the unstable engine can put you in some deep trouble in the middle of the road. 


You can’t run an engine that’s designed to work with a turbo or super charger without the boost being active. P0046 Duramax directly indicates the inactivity or malfunction of the boost system. So, you can’t take the matter lightly. 

Yes, everybody agrees that troubleshooting this code is pretty hard and lengthy, even for a professional mechanic sometimes. That’s why we’re telling you not to delay any moment when this issue arises. 

We’ve shown you how to deal with this OBD II code like an expert. Thus, you better follow the symptoms and check the validity of the code first. If the code’s real, don’t waste any time and go for troubleshooting.

Related Posts:

Similar Posts