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P00E4 Powertrain

Exhaust Heat Exchanger Exhaust Bypass Valve A Stuck Closed

The exhaust heat exchanger bypass valve A is stuck closed. Risk of overheating because exhaust always passes through the heat exchanger.

Affected components

  • Exhaust bypass valve a
  • Heat exchanger

Common causes

  • High likelihood: Valve stuck closed by carbon
  • Low likelihood: Carbon or debris buildup preventing free movement
  • Low likelihood: Component wear with age - mechanical play

Diagnostic notes

  • The malfunction indicator lamp may illuminate
  • This code can affect emissions
  • A drive cycle may be required after repair
  • Reduced-power or limp mode may occur

Sources

Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.

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