P0241 – Turbo/Super Charger Boost Sensor “B” Circuit Low

P0241 is a turbocharger-related trouble code that can leave you wondering if your engine is about to fail or if it’s just a sensor glitch. This code points to an issue with the turbocharger wastegate solenoid “B” circuit range or performance, which affects how your engine builds and controls boost. If you’re noticing low power, odd turbo noises, or a check engine light after hard acceleration, P0241 is worth taking seriously. In this guide, you’ll learn what it means, common causes, symptoms, and how you or your mechanic can fix it.

What Does P0241 Mean?

P0241 is an OBD-II diagnostic trouble code that indicates a problem in the control circuit for the turbocharger wastegate solenoid “B.” The ECU (engine control unit) monitors electrical voltage and response from this solenoid. When the readings are out of the expected range, it sets P0241.

In plain terms, your ECU is not happy with how one of the boost-control solenoids is behaving. That can lead to incorrect turbo boost levels, reduced power, and sometimes limp mode to protect the engine.

Quick Reference

• Code: P0241
• Meaning: Turbocharger wastegate solenoid “B” range/performance (circuit issue)
• Main systems: Turbocharger, boost control, engine management
• Risk level: Moderate – may cause power loss and drivability issues
• Typical fix: Electrical repair, solenoid replacement, hose/connector repair

Real-World Example / Field Notes

In the shop, I often see P0241 on turbocharged vehicles that have recently had performance work or basic maintenance done near the turbo area. One Subaru owner came in complaining of weak acceleration and a sudden check engine light after replacing a cracked intercooler hose. Scan data showed P0241 with low commanded boost. A closer look found a wastegate solenoid connector that wasn’t fully seated and a brittle vacuum line that cracked during the hose swap. After repairing the line and securing the connector, boost came back to normal and the code never returned.

Symptoms of P0241

• Check engine light illuminated, sometimes with reduced power mode
• Low power or sluggish acceleration, especially under boost or highway merging
• Inconsistent boost – turbo feels like it comes and goes, or surges
• Poor fuel economy due to inefficient boost control and richer mixtures
• Unusual turbo noises such as whooshing, whistling, or chuffing under load
• Harsh shifting on automatics if the transmission adapts to reduced engine torque
• Possible limp mode where the ECU limits power to protect the engine

Common Causes of P0241

Most Common Causes

• Faulty wastegate solenoid “B”: Internal electrical failure or sticking valve causing incorrect response.
• Damaged wiring or connector to the solenoid: corrosion, broken wires, or loose pins affecting voltage and signal.
• Vacuum/boost hose issues: cracked, loose, or disconnected hoses between the solenoid, turbo, and wastegate actuator.
• Aftermarket modifications: boost controllers, tunes, or deleted/relocated solenoids confusing the factory ECU strategy.
• Contaminants in the solenoid: oil mist, dirt, or moisture causing the valve to stick or respond slowly.

Less Common Causes

• Faulty wastegate actuator (mechanical): sticking or seized actuator that makes the solenoid look bad to the ECU.
• ECU internal fault: rare, but possible if other unrelated electrical codes are present.
• Incorrect or low system voltage: weak battery or charging problems affecting solenoid performance.
• Previous poor repairs: incorrect pin-outs, spliced wires, or wrong solenoid part number installed.
• Severe boost leaks: large leaks can cause the ECU to command unusual solenoid duty cycles and trigger range/performance faults.

Diagnosis: Step-by-Step Guide

You’ll want a basic scan tool, a digital multimeter (DMM), and ideally a handheld vacuum pump. Access to wiring diagrams and service information for your specific vehicle is very helpful. A bidirectional scan tool that can command the wastegate solenoid on and off makes diagnosis faster, but you can still do a lot with a basic reader.

1. Confirm the code and record freeze-frame data. Scan for P0241 and any related turbo or boost codes. Note engine load, RPM, and speed when the code set. Clear the code and see if it returns on a short test drive.
2. Perform a visual inspection. With the engine off, inspect the wastegate solenoid “B,” its wiring harness, and all nearby vacuum/boost hoses. Look for cracks, oil saturation, loose connectors, or rubbed-through wires near hot exhaust or sharp brackets.
3. Check connectors and terminals. Unplug the solenoid and inspect pins for corrosion, bent terminals, or moisture. Gently tug each wire to spot broken conductors under the insulation. Clean and reseat the connector.
4. Test solenoid resistance. Using a multimeter, measure resistance across the solenoid terminals. Compare the reading to factory specs. An open circuit (infinite resistance) or a dead short (near 0 ohms) usually means the solenoid is bad.
5. Verify power and ground. With the key on, back-probe the connector to check for proper supply voltage and a solid ground. If power or ground is missing, trace the circuit back through fuses, relays, and harness sections.
6. Check solenoid operation. If you have a scan tool that can command the solenoid, listen and feel for it clicking on and off. You can also apply vacuum (if applicable) and watch for changes in flow or actuator movement when the solenoid is energized.
7. Inspect vacuum/boost hoses and actuator. Use a vacuum pump on the wastegate actuator to confirm it moves smoothly and holds vacuum. Replace any brittle or oil-soaked hoses. Check for kinks or incorrect routing from previous repairs.
8. Look at live data and Mode $06. Monitor boost pressure, commanded boost, and wastegate duty cycle on a road test. If available, review Mode $06 data for turbo or solenoid-related test results to see if you’re close to failure thresholds.
9. Check for aftermarket tuning or hardware. If the vehicle has a tune, manual boost controller, or non-OEM turbo parts, verify that the wastegate solenoid is still wired and plumbed correctly and that the tune matches the hardware.
10. Perform a final road test. After repairs or adjustments, clear codes and drive under similar conditions to when P0241 set. Confirm that boost feels normal and the code does not return.

Pro tip: On many turbo cars, the wastegate solenoid is mounted in a hot, cramped spot. Heat shields and brackets often need to come off for a proper inspection. Take the extra time to pull them; you’ll catch issues that are invisible from above.

Possible Fixes & Repair Costs

Fixing P0241 usually involves restoring proper control of the wastegate solenoid circuit and ensuring the turbo system is sealed and functioning as designed. Common repairs include replacing the wastegate solenoid “B,” repairing damaged wiring or connectors, and replacing cracked vacuum/boost hoses. In some cases, you might need a new wastegate actuator or to correct previous aftermarket modifications.

Typical repair costs vary widely. A simple hose or connector repair might be under $100. Replacing a wastegate solenoid generally runs $150–$350 parts and labor, depending on access. Wiring harness repairs can range from $100–$400 based on complexity. If a turbo actuator or related hardware is involved, you could see $400–$900 or more. Labor rates, vehicle make, and how buried the components are will heavily influence the final bill.

Can I Still Drive With P0241?

In many cases you can still drive with P0241, but you may notice reduced power, inconsistent acceleration, and higher fuel consumption. The ECU may limit boost to protect the engine, which makes the car feel sluggish. Short trips to get home or to a repair shop are usually fine if the vehicle still runs smoothly and no severe noises or smoke are present. However, towing, hard acceleration, or long highway drives with a known boost-control fault are not a good idea, because you risk overboost or prolonged stress on the turbo and engine.

What Happens If You Ignore P0241?

If you ignore P0241, you can end up with chronic low power, poor fuel economy, and potential turbocharger damage if the system occasionally overboosts. Long-term driving with incorrect boost control can stress pistons, head gaskets, and catalytic converters. It also makes it harder to pass emissions tests and can mask other emerging turbo or engine issues that show up later as more expensive repairs.

Last updated: February 13, 2026

Vehicles Commonly Affected by P0241

P0241 is most common on turbocharged vehicles where electronic wastegate control is standard. You’ll often see it on Subaru WRX and Forester XT models, Volkswagen and Audi 1.8T and 2.0T engines, Ford EcoBoost vehicles (Focus, Fusion, F-150), GM turbocharged four-cylinders (Chevy Cruze, Sonic, Buick Regal), and some Hyundai/Kia 1.6T and 2.0T engines. Diesel trucks with electronically controlled wastegates or VGT turbos can also set similar codes. Any turbocharged car or SUV with multiple wastegate solenoids can potentially trigger P0241 when the “B” circuit acts up.