P2591 moderate

Turbocharger Boost Control 'B' Position Exceeded Learning Limit

The P2591 code means the vehicle's onboard diagnostic system has detected: Turbocharger Boost Control 'B' Position Exceeded Learning Limit. This is a moderate severity code.

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Keep driving?
Short distances only
DIY difficulty
hard
Estimated cost
$300 - $1000 (parts and labor)
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Common Symptoms

  • Check Engine Light on
  • Turbo performance inconsistent
  • Reduced power under load
  • Engine hesitation at mid-RPM range
  • Boost gauge reads lower than normal

Probable Causes (Ranked by Likelihood)

  • Variable geometry turbo vanes sticking Very High
  • Boost control actuator worn beyond adjustment range High
  • Charge air cooler (intercooler) leak Moderate
  • PCM learning values need reset Moderate

Step-by-Step Diagnostic Procedure

  1. Read freeze frame data and confirm P2591 is stored

  2. Monitor boost control position at various RPMs and loads

  3. Inspect variable geometry turbo mechanism for free movement

  4. Check intercooler and all boost pipes for leaks

Frequently Asked Questions

What does P2591 mean?

P2591 indicates an issue with the turbocharger boost control 'b' position exceeded learning limit. This affects the PCM's ability to properly control turbocharger boost levels.

Can I drive with a P2591 code?

You can drive short distances with reduced power. Have it repaired promptly to avoid further turbo system damage.

How much does it cost to fix P2591?

Repairs typically cost $300 - $1000, depending on the specific component that has failed.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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