Turbocharger/Supercharger Boost Pressure A Actuator Stuck Open
The P2644 code means the vehicle's onboard diagnostic system has detected: Turbocharger/Supercharger Boost Pressure A Actuator Stuck Open. This is a critical severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $300 - $1500 (parts and labor)
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Common Symptoms
- No turbo boost
- Significant loss of power
- Black smoke under acceleration
- Check engine light on
Probable Causes (Ranked by Likelihood)
- Wastegate actuator stuck open Very High
- Broken wastegate actuator rod High
- Vacuum or boost leak at actuator Moderate
- Turbo bearing failure preventing spool-up Low
Step-by-Step Diagnostic Procedure
-
Inspect wastegate actuator for free movement
-
Check actuator vacuum or pressure lines
-
Test actuator with manual vacuum pump
-
Inspect turbo shaft for play indicating bearing wear
Frequently Asked Questions
Why do I have no turbo boost?
The wastegate is stuck open, allowing exhaust gas to bypass the turbine wheel instead of spinning it. No exhaust drives the turbine, so no boost is produced.
Can I drive without turbo boost?
The engine will run but with significantly reduced power. Drive only at low speeds and avoid heavy loads. Highway driving may be difficult.
What causes a wastegate to stick open?
Carbon buildup, corrosion, a broken actuator rod, or a loss of control pressure to the actuator can all cause the wastegate to remain open.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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