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P20D5PowertrainStop Driving

Exhaust Aftertreatment Fuel Injector "B" Stuck Open

This code means the PCM/ECM has detected a stuck-open condition affecting exhaust aftertreatment fuel injector "b. The problem is usually tied to fuel pressure control, injector operation, or the electrical circuit that commands the component. Depending on the failure, the engine may start hard, idle rough, hesitate, or lose power.

Stop driving immediately — continuing to drive may cause serious engine or safety damage.

What You Might Notice

  • Check Engine Light illuminated
  • Hard starting or extended cranking
  • Rough idle or misfire
  • Reduced power under load
  • Poor fuel economy

Most Common Causes

  1. 1

    Faulty injector, regulator, pump, or fuel pressure sensor

  2. 2

    Open, shorted, or corroded wiring/connectors

  3. 3

    Restricted fuel filter or weak fuel supply

  4. 4

    Vacuum leak or unmetered air entering the engine

  5. 5

    PCM command/driver fault

How to Diagnose It

  1. 1

    Check Faulty injector, regulator, pump, or fuel pressure sensorInspect for signs of failure and test before replacing.

  2. 2

    Check Open, shorted, or corroded wiring/connectorsInspect for signs of failure and test before replacing.

  3. 3

    Check Restricted fuel filter or weak fuel supplyInspect for signs of failure and test before replacing.

  4. 4

    Check Vacuum leak or unmetered air entering the engineInspect for signs of failure and test before replacing.

  5. 5

    Check PCM command/driver faultInspect for signs of failure and test before replacing.

How to Fix It

  1. 1

    Check live data and fuel pressure against specifications

  2. 2

    Inspect and repair wiring/connectors in the affected circuit

  3. 3

    Test and replace the faulty injector, regulator, pump, or sensor

  4. 4

    Repair vacuum leaks or fuel supply restrictions

  5. 5

    Clear the code and confirm the repair with a road test

Need a deeper diagnosis?

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