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FuelSeverity Medium: diagnose soon

P0271Cylinder 4 Injector "A" Circuit High

What it means

The voltage on the control side of the cylinder 4 injector is higher than expected when the injector is not switched. The circuit is usually open or shorted to voltage, so the injector may not open.

Symptoms

  • Misfire or rough running on cylinder 4
  • Loss of power
  • Check engine light

Common causes

  • Open injector winding or wire
  • Control wire shorted to battery voltage
  • ECU driver fault

What to check first

  1. Measure the injector resistance
  2. Check the control wire for shorts to ground and to voltage
  3. Scope the injector to see whether the ECU switches it
Can I drive with P0271? Usually yes for a short distance, but performance or economy may suffer and the fault can get worse. Diagnose it soon.

Generic OBD-II meaning. Manufacturer-specific meanings and checks can differ; always check the service information for the car.

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P0271: questions and answers

What does P0271 mean?

P0271: Cylinder 4 Injector "A" Circuit High. The voltage on the control side of the cylinder 4 injector is higher than expected when the injector is not switched. The circuit is usually open or shorted to voltage, so the injector may not open.

What are the symptoms of P0271?

Misfire or rough running on cylinder 4. Loss of power. Check engine light.

What causes P0271?

Open injector winding or wire. Control wire shorted to battery voltage. ECU driver fault.

How do you diagnose P0271?

1. Measure the injector resistance 2. Check the control wire for shorts to ground and to voltage 3. Scope the injector to see whether the ECU switches it

Can I drive with P0271?

Usually yes for a short distance, but performance or economy may suffer and the fault can get worse. Diagnose it soon.