Guide To P0046 OBD Error Code Solutions

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Is your Check Engine Light illuminated on the car’s dashboard? Are you experiencing sudden drop in the fuel economy with stalling of the engine? Or is there any smoke coming from the exhaust pipe? Then, there might be a possibility of an issue with the Boost Control Circuit of the car thus indicating OBD Code P0046 error.

This error usually occurs when the Engine Control Unit detects an out of range reading from the Boost Control Unit and thus the code gets stored in the PCM (Powertrain Control Module). This causes abnormalities in the air pressure, which affects the air to fuel ratios and thus the combustion process, ultimately affecting the engine performance.

What causes problem of Turbo/Super Charger Boost Control Solenoid Circuit Range/Performance?

• Intake manifold vacuum leaks
• Dirty/restrictive air cleaner
• Stuck open or closed wastegate
• Intercooler leakages
• Bad gasket or loose connections between the exhaust manifold and the turbocharger
• Turbocharger and the inlet pipe loose connections
• Faulty boost sensor
• Boost sensor circuit wiring open/short
• Loose/disconnected/damaged electrical connectors in the boost sensor circuit
• Turbo failure from leakages and blade damages

1. Engine Control Unit - If the ECU interprets the data wrongly, this can lead to improper air pressure thus hampering the performance. Replace faulty parts now!
2. Turbocharger - Faulty turbocharger will reduce the internal combustion of the engine, thus affecting the power output. If faulty, replace immediately.
3. Supercharger - Faulty supercharger will lead to less oxygen entering the combustion chamber, which will cause decreased power output. Replace faulty parts now!
4. Intake Manifold - Improper air to fuel ratios will not let the fuel burn properly and reduce engine power due to faulty air intake manifold. Thus, it should be replaced immediately.
5. Air Cleaner - If the cleaners are dirty and damaged, the air fill not be cleaned properly, lowering the engine performance. Replace air filters now!
6. Exhaust Manifold - Damaged exhaust manifolds can cause loud engine noises, loss of accelerations and sometimes burning smell from the engine bay as well. If you notice these indications, check for the faults in the exhaust manifolds and replace it.
7. Intake Pipe - Check for leakages the intake pipe as it will drastically decrease the engine power and thus should be replaced when found damaged.
8. Electrical Connectors - Always check for faulty circuit connectors first when doing diagnosis as they are the first reasons for flashing of the OBD code. Buy new parts from us.
9. Intercoolers - Intercoolers are important when it comes to increasing the air density and thus increasing the engine power. Therefore, always replace the faulty intercoolers.
10. Diagnostic Tools - Professional OBD scan tools are necessary to diagnose a problem. Buy quality diagnostic tools from us now!

In addition to service/check engine soon lamp illumination, code P0046 may lead to the following symptoms:

Common Symptoms

• Reduced engine performance
• Abnormal noises from the vehicle’s under hood
• Increased engine and/or transmission temperatures
• Emission of black smoke from the exhaust
• Faulty spark plugs
• Cylinder detonation due to increased engine temperatures
• Reduction in engine acceleration

The mechanic has to do many tests to find the problem and repair, before repairing or replacing components simply by assuming that the issue is solely due to a vacuum or oil leak, or bad wiring or connectors.

If the boost gauge is operating in coordination with the running conditions, then you should check closely for leaks on the intake system, hoses, clamps, intercooler and piping, when the vehicle is sitting off or at idle.

If everything seems in perfect condition, then check for the faults in the boost sensor and the ECU and replace/repair as per requirement.

Always use an OBD-II scanner to identify the code, then reset the code and test the vehicle to see if the code returns.

If the P0046 code returns, then the mechanic should follow the test procedure:

• Check the turbo or supercharger system for loose connections, including hoses and lines being cracked or damaged.
• Check the boost sensor wiring for loose connections, damaged wiring, or faulty sensor.
• Ensure that the boost pressure is not erratic during operation and driving for normal range of 9 to 14 PSI pressure.
• Examine the turbocharger for damaged blades, wobbly shaft rotation, worn bearings, oil leaks and correct control valve or wastegate operation.

Common mistakes when diagnosing the P0046 Code

• Don’t assume the components to be bad without carefully inspecting the system first.
• Failure to flush all debris and obstructions from the turbocharger oiling system can lead to repeated turbo failure.
• Replacement of turbocharger without complete testing the bypass valve or wastegate function and electrical circuitry is also the cause of wrong diagnosis.