Code result
P25B4
Turbocharger/Supercharger Wastegate A Stuck Closed
Moderate severity
What it means
Wastegate A is mechanically stuck closed. The turbo cannot bleed off exhaust at high load — boost overshoots the setpoint, risking overboost cut-off and damage to the turbo bearing. Carbon-locked flap, seized linkage or aged actuator are typical causes.
Is it safe to drive?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Carbon-locked wastegate flap
highOne of the most commonly reported causes for this code — check this first.
Seized linkage
mediumA plausible cause — test and verify before replacing parts.
Carbon or debris buildup preventing free movement
lowLess common, but worth ruling out after the more likely causes.
Related help
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