The wastegate solenoid is how the engine computer turns boost up and down. When it fails, the turbo may make too little boost or too much. A P0247 code means the engine computer found a problem with turbocharger wastegate solenoid B.
This guide explains how the solenoid controls boost, what usually fails and how to test it.
P0247 Code Breakdown
Every OBD-II code follows the same five-character pattern set by the SAE J2012 standard. Each character narrows down which system has the fault. This table shows what each part of the code tells you.
| Character | Meaning | What It Tells You |
|---|---|---|
| P | Powertrain | The fault is in the engine or transmission systems. |
| 0 | Generic (SAE) code | The definition is the same on every OBD-II vehicle. |
| 2 | Fuel and air metering | The fault involves fuel and air metering, such as injectors, the fuel pump, throttle sensors or boost control. |
| 47 | Specific fault | Turbocharger Wastegate Solenoid B Malfunction |
What the P0247 Code Means
The SAE J2012 standard defines the P0247 code as Turbocharger Wastegate Solenoid B Malfunction. Wastegate solenoid B is a second boost control solenoid. It is used on some twin turbo engines, with one solenoid per turbo, and on engines with more than one stage of boost control. Check your service manual to see which turbo it controls.
The powertrain control module (PCM) pulses the solenoid on and off many times per second. By changing the on-time, it changes how much pressure reaches the wastegate actuator, which sets how far the wastegate opens and how much boost the turbo makes.
Some newer engines use an electric wastegate actuator with its own position sensor instead of a solenoid and hoses. On those, the same codes can point to the actuator motor or its circuit.
This is the general circuit code for the wastegate solenoid B. The PCM saw a circuit voltage or current that did not match its command, such as an open, a short or a part that does not respond, but the code does not say which.
Symptoms of a Bad Wastegate Solenoid B
Boost control problems usually show up as power problems. Common signs of a P0247 code include:
- Check engine light on
- Low boost and sluggish acceleration
- Overboost surges followed by reduced power
- Limp mode
- Boost gauge that reads lower or higher than normal
- Whistling or hissing from a cracked hose
A solenoid that fails with no power usually leaves the wastegate at its spring setting, which gives low base boost. A solenoid that sticks or a hose that falls off can cause either low boost or overboost, depending on the design.
Common Causes of the P0247 Code
A general circuit fault can sit anywhere in the circuit. These are the usual causes:
- Loose or corroded connector. Heat and moisture attack the pins.
- Damaged wiring. Wires can chafe, break or melt near hot parts.
- Failed wastegate solenoid B. The coil opens or shorts inside.
- Blown fuse or lost power feed. The part cannot work without its supply.
- PCM driver fault. Rare, and often caused by a shorted coil.
Tools You Will Need
You can do most of this testing at home with basic tools:
- OBD-II scan tool that shows boost and solenoid duty cycle
- Digital multimeter and test light
- Hand vacuum and pressure pump
- Hose routing diagram for your engine
- Replacement silicone or rubber hose
How to Diagnose the P0247 Code
Start with the hoses and connector, since they fail more often than the solenoid itself.
Check Live Data and Command the Part
With the engine running, look at the wastegate solenoid B duty cycle along with desired and actual boost. If your scan tool can command the solenoid, turn it on and off and listen for a click.
Check Power and Ground
Unplug the wastegate solenoid B and turn the key on. Check for battery voltage on the feed wire with a test light. On most designs, the PCM switches the ground side, so a test light across the connector should flicker or light when the part is commanded on.
Measure Coil Resistance
Measure across the wastegate solenoid B terminals. Many boost control solenoids read about 20 to 40 ohms, but check the specification for your part. An open reading points to a high circuit code, and a near-zero reading points to a low circuit code.
Check the Wiring for Shorts and Opens
With the battery disconnected and the PCM unplugged, check the control wire for continuity end to end and for shorts to ground and to power. A good wire reads under 1 ohm end to end.
Compare Desired and Actual Boost
During a brief, safe acceleration, watch desired boost, actual boost and solenoid duty cycle. If the duty cycle rises but boost does not follow, look for a hose, wastegate or leak problem. If boost overshoots the target, the wastegate may not be getting its signal.
Repairs That Fix the P0247 Code
Match the repair to what your tests found. Then clear the code and drive under the same conditions that set it.
- Replace cracked or loose hoses and route them as the diagram shows.
- Repair the connector or wiring
- Replace wastegate solenoid B if its resistance is out of range or it sticks.
- Free or repair a sticking wastegate or actuator.
- Fix boost leaks in the intake and intercooler piping.
After any repair, clear the codes and road test while watching desired and actual boost. Boost should rise quickly to the target and settle there without spiking or falling short.
Common Mistakes to Avoid
These mistakes waste money or leave the real fault in place:
- Replacing the wastegate solenoid B before checking power and the connector
- Ignoring a blown fuse that points to a shorted coil
- Routing hoses to the wrong solenoid ports after replacement
- Replacing the turbo when a hose or solenoid is the cause
What Repairs Cost
The cost to fix a P0247 code depends on the cause. This table shows typical ranges for parts and labor.
| Repair | DIY Cost | Typical Shop Cost |
|---|---|---|
| Vacuum or pressure hose | $5 to $30 | $75 to $150 |
| Connector or wiring repair | $10 to $40 | $100 to $300 |
| Wastegate or boost control solenoid | $30 to $150 | $150 to $350 |
| Wastegate actuator | $80 to $400 | $300 to $900 |
Solenoid and hose repairs are usually quick, since the solenoid often sits on the inner fender or near the turbo intake. Actuator replacement costs more because it may need the turbo heat shield or more parts removed.
Is It Safe to Drive with a P0247 Code?
You can usually drive gently. Low boost makes the engine slow but is not harmful on its own.
If the fault causes overboost surges, avoid full throttle. Too much boost can damage the engine, and the PCM may cut power suddenly, which can be dangerous in traffic.
Related Codes
These codes often show up with this one or point to the same system:
| Code | Meaning |
|---|---|
| P0248 | Turbocharger Wastegate Solenoid B Range/Performance |
| P0249 | Turbocharger Wastegate Solenoid B Low |
| P0250 | Turbocharger Wastegate Solenoid B High |
| P0234 | Turbo/Super Charger Overboost Condition |
| P0299 | Turbo/Super Charger A Underboost Condition |
Fixing Wastegate Solenoid B
A P0247 code means the PCM found a fault with wastegate solenoid B. Hoses, connectors, wiring and failed solenoids cause most cases.
- Inspect the hoses and connector.
- Command the solenoid and listen for a click.
- Measure the solenoid resistance.
- Check the wiring for opens and shorts.
Frequently Asked Questions
Can a Cracked Hose Set the P0247 Code?
It can set a range or boost code more often than a circuit code, but a cracked hose is always worth checking. These small hoses get brittle from heat. A hose that has split or fallen off stops the solenoid from controlling the wastegate.
Where Is the Wastegate Solenoid?
It is usually mounted near the turbo, on the inner fender or on the intake piping, with two or three small hoses attached. On some diesels it controls vacuum instead of boost pressure. Your service manual shows the exact location.
What Is the N75 Valve?
N75 is Volkswagen and Audi’s name for the boost control solenoid on many turbo engines. It controls the pressure or vacuum that operates the wastegate or turbo vanes. A failing N75 is a common cause of low boost on those engines.
Why Does My Boost Spike and Then Cut Out?
A spike followed by a sudden loss of power usually means boost rose past the limit and the PCM cut power to protect the engine. A wastegate that does not get its control signal, from a failed solenoid or a split hose, is a common cause.
Can I Drive Without the Wastegate Solenoid?
The engine will usually run, but boost control will be poor. Without the solenoid, many engines stay at low spring boost, and some may overboost. Replace it soon to bring back normal power and protect the engine.