U0174 moderate

Lost Communication With Turbocharger Boost Control Module

The U0174 code means the vehicle's onboard diagnostic system has detected: Lost Communication With Turbocharger Boost Control Module. This is a moderate severity code.

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Keep driving?
Short distances only
DIY difficulty
hard
Estimated cost
$200 - $1000 (parts and labor)
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Common Symptoms

  • Check Engine Light illuminated
  • Reduced engine power or limp mode
  • Loss of turbo boost pressure
  • Poor acceleration response
  • Turbo wastegate not functioning properly

Probable Causes (Ranked by Likelihood)

  • Failed boost control module Very High
  • Damaged wiring to boost control solenoid High
  • Corroded connector at turbo assembly Moderate
  • Failed turbo wastegate actuator Moderate

Step-by-Step Diagnostic Procedure

  1. Check boost pressure with a scan tool at idle and under load

  2. Inspect wiring to the boost control solenoid and wastegate actuator

  3. Verify power and ground at the boost control module

  4. Check vacuum lines to the wastegate for leaks or disconnection

  5. Inspect the turbo assembly for oil leaks or mechanical damage

Frequently Asked Questions

Can I drive with code U0174?

You can drive short distances but expect significantly reduced power. The engine will likely enter limp mode to protect the turbocharger.

What causes U0174?

Usually a failed boost control module or damaged wiring near the turbocharger. Heat and vibration in the engine bay can degrade connections over time.

Is U0174 expensive to fix?

Costs range from $200 for wiring repairs to $1000 for module or actuator replacement. Turbo-related repairs tend to be labor intensive.

Sources

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

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