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P003A OBD-II Trouble Code: Turbocharger/Supercharger Boost Control "A" Position Exceeded Learning Limit

check engine light

P003A trouble code definition

The P003A OBD-II trouble code indicates the Electronic Computer Module (ECM) has detected an issue in the turbocharger or supercharger system, specifically about readings being outside acceptable parameters in regards to the engine’s boost.

What the P003A code means

In the most basic sense, the registration of the P003A code means the ECM noted a misalignment in the boost control A within the engine’s turbocharging or supercharging system. Such a misalignment can cause the engine to rev up to such a degree that other components of the system may be affected or damaged, such as push rods or rockers, due to an improper range of motion.

What causes the P003A code?

When the ECM detects an improper range of motion within the turbo- or supercharger through the on-board computer circuitry, it registers the P003A code and turns on the Check Engine Light on the vehicle’s dashboard. It may also be accompanied by other OBD-II trouble codes, such as P2563.

What are the symptoms of the P003A code?

In addition to the P003A code triggering the Check Engine Light to come on, the vehicle may display other symptoms, such as:

How does a mechanic diagnose the P003A code?

The first step in diagnosing the cause of the P003A OBD-II trouble code is to verify its existence. This is done by connecting a specialized scan tool (more technologically advanced than those found in auto parts stores) and seeing if that fault code registers. Using the data collected by the scan tool, a trained mechanic can then interpret that data to narrow down the cause of the P003A code. Other tests, such as a manufacture pinpoint test or additional scans following the clearing of codes may also be necessary to gain insight into the nature of or severity of the issue.

Common mistakes when diagnosing the P003A code

When diagnosing the P003A OBD-II trouble code, the most common mistakes made by technicians are:

  • Not verifying the P003A code
  • Failing to perform a visual inspection of the turbocharger or supercharger
  • Forgetting to clear the P003A code after making repairs

How serious is the P003A code?

While a vehicle can still run once the P003A code has registered, the excessive range of motion of the vane within the turbo- or supercharger can ultimately harm other components, such as push rods or rockers. It is therefore inadvisable to continue driving a vehicle that has triggered the P003A code, and you should seek professional assistance in diagnosing and repairing the issue before the potential costs of the fix increase exponentially due to spreading damage.

What repairs can fix the P003A code?

After validating the P003A code with the proper scan tool, a mechanic may make the following repair(s):

  • Adjusting the vane within the turbocharger or supercharger
  • Replacing the turbocharger or supercharger

Additional comments for consideration regarding the P003A code

Any time an OBD-II fault code registers with the ECM, such as the P003A code, discovering the cause of the code and determining what repairs are necessary can take time - up to several hours. Multiple scans using a specialized scan tool may be in order along with other tests to be sure the proper course of action is taken. Also, after any repairs have been completed or parts replaced, the mechanic should test drive the vehicle and perform one last scan to be sure the issue has been resolved.

Need help with a P003A code?

YourMechanic is happy to connect you with a mobile mechanic to diagnose and repair problems with your vehicle registering the P003A code and can even come to your home or office to do the job. Get a quote and make an appointment online or speak with a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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