What it means
Same as wastegate A stuck open, applied to the second wastegate (twin-turbo, sequential or two-stage). Boost control tracks commanded vs. actual manifold pressure; persistent deviation means wastegate, vanes, hose or actuator are not delivering the requested pressure.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Wastegate B controls exhaust flow through the second turbocharger or boost stage, helping regulate how much boost reaches the engine. The control module compares commanded boost with measured manifold pressure and sets this code when boost stays below target because wastegate B is not closing or moving as expected.
Common causes
Most likely first.
- Seized wastegate linkage
- Carbon or debris buildup preventing free movement
- Component wear with age - mechanical play
Symptoms
- Check-engine light may come on
- Reduced engine power or boost may occur
How to diagnose it
- Use a scan tool to save freeze-frame data and compare commanded boost with actual manifold pressure under the conditions that set the code.
- Inspect wastegate B’s linkage, flap, actuator, and nearby hoses for looseness, damage, carbon buildup, or anything preventing movement.
- With the engine off and cool, check whether wastegate B’s linkage moves freely through its intended travel without binding or excessive play.
- Inspect the actuator hoses, connectors, and wiring for leaks, chafing, corrosion, or disconnected parts, taking care to distinguish wastegate B from wastegate A.
- Test wastegate B’s actuator and control circuit using the manufacturer’s procedure, then compare its response with the commanded position or boost request.
Common fixes
- Free carbon or debris that is binding wastegate B’s linkage or flap.
- Repair or replace a leaking, disconnected, or damaged actuator hose for wastegate B.
- Repair damaged wiring or connectors in wastegate B’s control circuit.
- Replace a seized or worn wastegate B actuator or linkage component.
Can I keep driving?
You can usually drive gently to a safe place if power is normal, but avoid hard acceleration, towing, and high engine load because boost may be limited. Stop if power drops sharply or the engine shows signs of overheating or abnormal operation.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.