P0248 — Turbocharger/Supercharger Wastegate Solenoid “B” #

The code description may vary depending on the vehicle manufacturer. Always consult the specific service information for your vehicle.

Known variations of the code label:

• “Turbocharger Wastegate Solenoid ‘B’ Circuit High” (Ford, GM, FCA/Stellantis)
• “Supercharger Bypass Solenoid ‘B’ Circuit Range/Performance” (Mercedes-Benz)
• “Wastegate Solenoid ‘B’ Control Circuit Malfunction” (Volkswagen/Audi)

Summary of code P0248 #

P0248 is a diagnostic trouble code (DTC) indicating the engine control module (ECM) has detected an issue with the electrical circuit of the wastegate solenoid ‘B’ on a turbocharged or supercharged engine. The wastegate solenoid is an electrically actuated valve that helps control boost pressure by opening or closing the wastegate. The designation “‘B'” refers to a specific solenoid in systems with multiple boost control solenoids. When this code is set, the solenoid may not be functioning correctly, potentially causing erratic turbo or supercharger operation. This can result in engine performance issues, reduced power, or possible engine damage if left unresolved.

Frequent symptoms for code P0248 #

When P0248 is present, you may notice a variety of performance concerns. These can range from subtle to pronounced, depending on the failure mode and how your ECM responds. In some cases, the engine may enter “limp mode” to protect itself, while in others, you might simply notice a decrease in power or abnormal turbo response. Common symptoms include:

• Check Engine Light illuminated
• Reduced engine power, especially under acceleration
• Poor turbocharger or supercharger response
• Unusual noises from the turbo area, such as hissing or fluttering
• Higher than normal exhaust emissions
• Surging or hesitation during throttle application

Probable causes (in order of frequency) for code P0248 #

Several issues can trigger the P0248 DTC. Some are electrical, while others are mechanical or even related to the vehicle’s computer (ECM). Based on technician experience and OEM data, the most common causes are:

1. Faulty wastegate solenoid ‘B’ (internal electrical failure)
2. Open or short circuit in the wastegate solenoid ‘B’ wiring harness
3. Poor electrical connections or corrosion at the solenoid connector
4. Faulty ECM (rare)
5. Mechanical binding or sticking of the wastegate actuator
6. Aftermarket modifications interfering with boost control wiring

Step-by-step diagnostic procedure for P0248 #

Accurate diagnosis is essential to avoid unnecessary parts replacement. Follow these steps to pinpoint the issue efficiently:

• Verify the code: Use a professional scan tool to confirm P0248 is present and check for related boost control or wiring codes.
• Visual inspection: Examine the wastegate solenoid ‘B’, its wiring, and connectors for damage, corrosion, or loose pins.
• Check solenoid operation: Using a multimeter, measure resistance across the solenoid terminals. Compare to OEM specifications (typically 20–40 ohms; verify for your vehicle).
• Test wiring continuity: Unplug the solenoid and ECM connectors. Check for open circuits, shorts to ground, or shorts to power in the wiring harness.
• Command solenoid with scan tool: Some advanced tools allow you to activate the solenoid and listen for a clicking sound or feel for actuation.
• Inspect wastegate actuator: Ensure the mechanical linkage is not seized or obstructed (engine off, cold).
• If all tests pass: Suspect a rare ECM driver issue and consult OEM service bulletins.

Possible repairs for code P0248 #

Based on the root cause found during diagnosis, repairs may include:

• Replacing the wastegate solenoid ‘B’ (most common fix)
• Repairing or replacing damaged wiring or corroded connectors
• Cleaning electrical contacts and applying dielectric grease
• Repairing or replacing the wastegate actuator mechanism (if binding is present)
• Reflashing or replacing the ECM (only after all other options are exhausted and verified)
• Restoring proper installation if aftermarket mods have altered wiring

Is it safe to drive with code P0248? #

Limited — While some vehicles may remain drivable with the P0248 code, it is not recommended to ignore it. An inoperative wastegate solenoid can cause uncontrolled boost, risking engine or turbocharger damage. In many cases, the car will run in a reduced power mode to protect the engine. Always address this code as soon as possible to avoid costly repairs or unsafe driving conditions.

Vehicles most commonly affected by P0248 #

This code is most often seen on vehicles equipped with turbocharged or supercharged engines, particularly those with multiple boost control solenoids. It is frequently reported on:

• Ford EcoBoost and Power Stroke turbo engines
• Volkswagen and Audi 1.8T/2.0T (TSI, TFSI) engines
• Mercedes-Benz AMG models with superchargers
• GM turbocharged models (Chevrolet, Buick, GMC)
• Dodge and Jeep turbocharged 2.0L/2.4L engines

Common mistakes & best practices for P0248 #

Even experienced technicians can make avoidable errors when dealing with turbo wastegate codes. Avoid these pitfalls for a faster, more accurate repair:

• Replacing the solenoid without checking wiring or connectors first
• Overlooking corrosion or water intrusion at harness connectors
• Assuming the code is caused by the turbo itself (the problem is usually electrical, not mechanical)
• Not using OEM wiring diagrams for pinout and color codes
• Clearing the code before confirming the repair, which can erase valuable freeze-frame data

Quick FAQ for code P0248 #

Still have questions? Here are fast answers to the most common concerns about this code:

Q: Can a dirty air filter cause code P0248?
A: No, a dirty air filter will not trigger this code. P0248 is specific to the electrical circuit of the wastegate solenoid ‘B’.

Q: Will a faulty wastegate solenoid cause turbo lag?
A: Yes, if the solenoid fails to operate, it can cause either excessive turbo lag or uncontrolled boost, depending on how it fails.

Q: Do I need to reset the ECM after repairs?
A: After repairs, clear the code with a scan tool. The ECM will recheck the system and turn the check engine light off if the problem is resolved.

If you have further questions, always consult your vehicle’s service manual or a qualified technician. Addressing boost control issues promptly protects your engine and ensures optimal performance.