P0247 Code: Turbocharger Wastegate Solenoid B Malfunction

Quick Answer

• What it means: The P0247 code indicates an electrical malfunction in the circuit for the turbocharger wastegate solenoid "B", meaning the engine computer cannot properly control boost pressure.
• Severity: Moderate to High. You can safely drive the vehicle home or to a shop, but aggressive driving should be avoided to prevent potential overboost engine damage or extreme loss of power.
• Most common cause: A failed wastegate solenoid B or damaged wiring leading to the solenoid.

What the P0247 code means

The official OBD-II definition for P0247 is "Turbocharger Wastegate Solenoid B Malfunction."

In plain English, this means your engine's computer (the Powertrain Control Module or PCM) has detected an electrical issue with the solenoid that controls the "B" wastegate on your turbocharger. Turbos force extra air into the engine to create more power. To prevent the turbo from generating too much pressure (overboost), a valve called a wastegate opens to let excess exhaust gas bypass the turbine.

The wastegate is operated by an actuator, which is controlled by the wastegate solenoid. The PCM sends electrical signals to this solenoid to continuously adjust boost pressure based on engine load, speed, and throttle position. If the PCM detects that the voltage or resistance in the wastegate solenoid "B" circuit is out of the expected range, it triggers code P0247. The "B" designation usually refers to a specific solenoid in a twin-turbo system or a secondary solenoid in a complex single-turbo setup.

Common symptoms

When the P0247 code is triggered, the PCM often puts the vehicle into a fail-safe "limp mode" to protect the engine and turbocharger from damage. You will likely experience:

• Illuminated Check Engine Light: The most immediate and obvious sign.
• Lack of Engine Power: The turbo may be disabled or restricted, making the car feel sluggish, especially during acceleration.
• Limp Mode Activation: The vehicle may restrict RPMs and shifting to protect the powertrain.
• Abnormal Turbo Noises: Whining, hissing, or fluttering sounds if the wastegate is stuck closed or open.
• Poor Fuel Economy: Inefficient air-to-fuel ratios caused by incorrect boost levels.
• Jerky Acceleration: Hesitation or surging when trying to build boost.

Common causes

From most to least likely, the causes of a P0247 code include:

1. Faulty Wastegate Solenoid B: The internal electromagnetic coil of the solenoid can burn out, short, or become stuck due to age and heat cycling.
2. Damaged Wiring or Connectors: The wires leading to the solenoid are often exposed to extreme under-hood temperatures. Melted insulation, corroded connector pins, or broken wires are very common.
3. Vacuum or Pressure Leaks: If the solenoid relies on vacuum or boost lines to actuate the wastegate, a cracked or disconnected hose can cause the system to fail, throwing a code.
4. Stuck Wastegate Actuator: If the mechanical linkage or actuator diaphragm fails, the solenoid may try to compensate, eventually leading to a circuit fault or performance code.
5. Faulty PCM (Rare): In very rare cases, the engine computer's internal driver that controls the solenoid circuit may have failed.

How a technician diagnoses it

An ASE-certified technician will follow a systematic approach to isolate the electrical fault:

1. Code Scanning and Freeze Frame Data: The technician hooks up a professional OBD-II scan tool to pull the P0247 code and review freeze-frame data. This shows the exact engine conditions (RPM, load, temperature) when the code was set. They will also look for related underboost or overboost codes.
2. Visual Inspection: A thorough check of the wastegate solenoid B, its electrical connector, and the wiring harness. They are looking for melted wires, corrosion, or disconnected vacuum/boost hoses.
3. Circuit Testing (Multimeter): The technician will disconnect the solenoid and measure its internal resistance using a digital multimeter. A healthy solenoid typically reads between 20 and 30 ohms (though specific specs vary by manufacturer). An "OL" (open loop) reading means the solenoid coil is broken and must be replaced.
4. Power and Ground Checks: With the key ON and engine OFF, the technician checks the harness side of the connector for proper voltage (usually 12V or 5V reference) and a solid ground. If voltage is missing, the wiring harness or a blown fuse is the culprit.
5. Bi-Directional Scan Tool Testing: Using an advanced scan tool, the technician will command the wastegate solenoid ON and OFF. They will listen for a definitive "click" from the solenoid and monitor boost pressure changes (if the engine is running) to ensure it is mechanically operating.
6. Actuator Testing: A vacuum or pressure pump (Mityvac) may be connected directly to the wastegate actuator to ensure the mechanical valve is moving freely and holding pressure.

Typical repair cost

The cost to resolve a P0247 code depends largely on the root cause and the specific make and model of the vehicle. Parts and labor typically break down as follows:

• Wastegate Solenoid Replacement: $150 – $400. The solenoid itself usually costs between $50 and $150. Labor is typically 1 to 2 hours, depending on how buried the turbocharger is within the engine bay.
• Wiring Repair: $100 – $250. If a wire is melted or broken, an hour or two of diagnostic and repair labor is usually required to splice in new wire and heat-shrink it.
• Vacuum Line Replacement: $50 – $150. Replacing dry-rotted or cracked hoses is inexpensive and fast.
• Wastegate Actuator/Turbo Replacement: $500 – $2,500+. If the wastegate itself is physically damaged or integrated into the turbo assembly, costs will escalate significantly.

(Note: Diagnostic fees usually range from $100 to $150, which is often rolled into the final repair cost if you have the shop perform the work.)

Can I keep driving with this code?

You can drive with a P0247 code for a short distance, such as home or to a repair shop, but it is not recommended to keep driving with it long-term.

If the wastegate fails in the "open" position, your vehicle will suffer a severe lack of power, making highway merging dangerous. If it fails in the "closed" position, the turbocharger can create too much pressure (overboost). Severe overboost can blow out engine seals, damage internal engine components, or destroy the turbocharger itself. It is best to drive gently and get the vehicle diagnosed as soon as possible.

Related codes

Technicians frequently see P0247 accompanied by other turbocharger-related DTCs, including:

• P0243: Turbocharger Wastegate Solenoid A Malfunction
• P0244: Turbocharger Wastegate Solenoid A Range/Performance
• P0248: Turbocharger Wastegate Solenoid B Range/Performance
• P0234: Turbocharger/Supercharger Overboost Condition
• P0299: Turbocharger/Supercharger Underboost Condition

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