P1203 – Boost Deviation Negative (BMW)

Description

P1203 BMW indicates the measured boost is lower than requested.

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Symptoms

  • Poor acceleration
  • Hesitation
  • Low boost

Causes

  • Boost leak
  • Weak turbo
  • Wastegate stuck open

Diagnosis

  • Check boost system
  • Inspect hoses
  • Test turbo

Repair

  • Fix boost leaks
  • Replace turbo
  • Repair wastegate

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