P0047 code definition

Turbo/Super Charger Boost Control Solenoid Circuit Low

What the P0047 code means

This code has varied definitions as provided by the manufacturer. The code means that the Engine Control Unit (ECU) has detected an out of range or abnormal reading of low operation in the turbocharger or supercharger boost control solenoid circuit. This code is related to circuit A as an area of the boost solenoid system circuit, as opposed to a particular malfunction or component.

What causes the P0047 code?

  • Vacuum leaks on the intake manifold or boost control

  • A dirty or restrictive air cleaner

  • The waste gate is either stuck open or closed

  • A plugged or leaking intercooler

  • Loose connections or bad gasket between the exhaust manifold and the turbocharger flange

  • A leaking connection between the turbocharger and the air intake pipe

  • A bad boost pressure sensor

  • Shorted or open wiring in the boost sensor circuit

  • Loose, corroded, or disconnected electrical connectors in the boost sensor 5-volt reference circuit

  • Turbo charger failure (usually caused by internal oil leaks and oil supply problems which can cause bearing failure and blade damage)

What are some of the symptoms of P0047 code?

  • Low or no boost and a loss of power during acceleration

  • Engine idle normal, but acceleration affected

  • Check Engine Light illumination once ECM has detected solenoid circuit low current condition (indicates open circuit)

How does a mechanic diagnose the P0047 code?

  • Scanning and verifying the code
  • Resetting the fault codes and performing a road test.

If the P0047 code returns, the following test procedure is necessary:

  • Inspecting for vacuum leaks

  • Inspecting the turbo or super charger system for loose connections, including hoses and lines being cracked or damaged

  • Checking the wiring on the boost sensor and related wiring for loose connections, damaged wiring, or faulty sensor

  • Examining the boost pressure during operation and driving for a normal range of 9 to 14 PSI pressure and insuring it is not erratic or too low

  • Inspecting the turbo charger for damaged blades, wobbly shaft rotation, worn bearings, oil leaks into turbo boost side, and correct control valve or waste gate operation

Common mistakes when diagnosing the P0047 code

Do not replace any component assuming it is bad without carefully inspecting the system. Mechanics have reported that failure to flush all debris and obstructions from the turbocharger oiling system can lead to repeated turbo failure related to the bearings on the turbocharger shaft. Replacing the turbocharger without complete testing of the by-pass valve or waste gate function and electrical circuitry is also the cause of common misdiagnosis.

How serious is the P0047 code?

This code is very serious and is usually preceded by the engine warning light coming on. It should be diagnosed as soon as possible to prevent engine internal damage or turbocharger failure. Minimize your driving until the problem can be repaired.

If the vehicle operates very poorly, do not drive it further. The vehicle can run roughly, backfire, have rich or lean fuel consumption, and operate in over or under boost conditions.

Often times, if the engine warning light comes on immediately at start up, the OBD- II system can be reset and the vehicle will operate normally.

What repairs can fix the P0047 code?

There are many causes for this code that relate to leaks and pressure loss in the system, but usually they related to hose, clamp and connection failures due to improper installation or simply age. Many times, an intake hose to the intercooler, or the intercooler itself, may have a leak, and would require replacement.

You can use a spray carburetor cleaner with a long plastic hose to spray directly at connections and hoses to see if the engine operation changes or improves. Modern vehicles are very complicated, so the using the hose with the carburetor cleaner allows for easy access to check specific areas for leaks. I have found cracked intake hoses to be a problem, usually on the bottom or out of site, that can cause intermittent problems only noted under load.

Additional comments for consideration regarding the P0047 code.

Many vehicles with mileage over 100,000 have momentary sensor problems that usually occur during start up or prolonged stress situations on the drive train.

If the engine warning light comes on and the vehicle seems to be operating normally, the OBD-II system can be reset using the scanner, and the problem may not reoccur. This is why it is important to verify the fault code and reset it before doing any repairs.

Need help with a P0047 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

This article originally appeared on YourMechanic.com as P0047 OBD-II Trouble Code: Turbo/Super Charger Boost Control Solenoid Circuit Low and was authored by John Nelson.


Share This Photo X