Possible causes

– Dirty Fuel Injector 4
– Faulty Fuel Injector 4
– Plugged Fuel Injector 4
– Fuel injector 4 harness is open or shorted
– Fuel injector 4 circuit poor electrical connection

Tech notes

Clogged or partially clogged fuel injector can cause this code. Start by performing an injector flush before replacing the injector.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– Engine Misfire
– Engine Run Rough
– Low MPG

P0271 BMW Description

Code P0271 is triggered when the Engine Control Module (ECM) detects a high voltage in the Fuel Injector 4 Circuit. During normal conditions the ECM turns the Fuel Injectors ON and OFF in the Fuel Injection System.