P0248
UniversalThe Powertrain Control Module (PCM) detects an out-of-range or performance issue with the turbocharger/supercharger wastegate solenoid "B" control circuit or mechanical operation.
Medium SeverityThis code indicates that the engine computer has detected an issue with the operation or performance of the turbocharger wastegate solenoid B. This typically means the wastegate is not controlling boost pressure as expected, leading to either reduced engine power or, in some cases, excessive boost.
⚠️ Before You Begin (Safety First)
Always allow the engine to cool completely before working on turbocharger components, as they can be extremely hot. Disconnect the negative battery terminal before attempting any electrical repairs. Wear appropriate safety gear, including gloves and eye protection.
Common Symptoms
- Check Engine Light illuminated
- Reduced engine power or acceleration (limp mode)
- Noticeable turbo lag
- Unusual noises from the turbocharger area (e.g., whining, whistling)
- Engine running rough or stalling at times
Common Causes
- Faulty turbocharger wastegate solenoid "B"
- Vacuum leaks in the wastegate control system (hoses, lines)
- Wiring issues (chafed, broken, corroded wires) or poor electrical connections to the solenoid
- Sticking or faulty wastegate actuator mechanism
- Clogged or restricted boost lines
- Malfunctioning Powertrain Control Module (PCM) (less common)
Frequently reported on: Vehicles with Turbocharged Engines
Diagnostic Steps
- Visually inspect all vacuum lines and hoses connected to the wastegate solenoid and actuator for cracks, disconnections, or leaks. Repair or replace as necessary.
- Check the electrical connector to the wastegate solenoid for corrosion or damage. Ensure it is securely plugged in.
- Using a multimeter, check for proper voltage and ground at the wastegate solenoid connector (refer to vehicle-specific wiring diagrams).
- With the engine off, manually test the wastegate actuator linkage to ensure it moves freely without sticking.
- If possible, test the resistance of the wastegate solenoid coil (compare to manufacturer specifications). A solenoid with incorrect resistance may be faulty.
- If the solenoid is suspected to be faulty and accessible, replacement may resolve the issue.
👨🔧 When to Call a Professional
If after checking for obvious vacuum leaks and electrical connections the issue persists, or if specialized diagnostic tools are required to test boost pressure and wastegate actuation, it's time to consult a professional mechanic.
Commonly Asked Questions
What does a wastegate solenoid do?
The wastegate solenoid controls the flow of exhaust gases to the turbocharger turbine, regulating boost pressure to prevent over-boosting and optimize engine performance.
Can I drive with a P0248 code?
While you might be able to drive, it is not recommended for long periods. The engine may have reduced power, and there's a risk of engine damage if the wastegate fails to prevent excessive boost.
Is a P0248 code always a bad wastegate solenoid?
No, the code indicates a range/performance issue. It could be a faulty solenoid, but also vacuum leaks, wiring problems, a sticking wastegate actuator, or even a problem with the turbocharger itself.
How can I test the wastegate solenoid?
You can typically test the solenoid by checking its electrical resistance with a multimeter, ensuring proper voltage/ground at its connector, and sometimes by applying vacuum/pressure to see if it actuates the wastegate.
What if I replace the solenoid and the code returns?
If the code returns, the issue is likely elsewhere in the wastegate control system, such as a sticking wastegate actuator, a persistent vacuum leak, or a wiring fault that was overlooked. Further diagnostics are needed.