P0270 OBD-II Trouble Code: Cylinder 4 Injector Circuit Low

Check Engine Light

P0270 code definition

Cylinder 4 Injector Circuit Low

What the P0270 code means

This diagnostic trouble code indicates that the powertrain control module has detected a lower reference voltage from the fuel injector on the number 4 cylinder than what was specified by the vehicle manufacturer.

What are the causes of the P0270 code?

  • The wiring or connector that is associated with the fuel injector on the number 4 cylinder has been damaged in some way.

  • The internal return spring inside the fuel injector on the number 4 cylinder may not be performing properly.

  • The powertrain control module could be malfunctioning.

What are the symptoms of the P0270 code?

How does a mechanic diagnose the P0270 code?

  • The first step a mechanic would take would be to locate the fuel injector on the number 4 cylinder. This may require the removal of a plastic engine cover in order to gain access.

  • The mechanic would then test the fuel injector using the service information provided by the manufacturer for proper function.

  • Next, the mechanic would ensure that the wiring and connector associated with the fuel injector on the number 4 cylinder are in good condition.

If the cause of this trouble code has not been discovered after these two tests have been performed:

  • The mechanic would then test the powertrain control module for faults using a high tech scan tool.

When a mechanic takes the time to go through all the proper steps necessary to diagnose an issue such as this one, the customer will be able to make a much more informed repair decision.

Common mistakes when diagnosing the P0270 code

A common mistake would be to test the wrong fuel injector. To prevent this from happening, it is imperative that an engine diagram is used that shows the correct cylinder order. Testing the wrong fuel injector can lead to misdiagnosis, wasted time, and wasted money.

How serious is the P0270 code?

Considering that this trouble code can cause the engine to misfire and therefore run poorly, this code would be considered serious. It is not in the best interest of the engine to drive for long periods of time with a misfire; it can cause damage to the catalytic converters as well as the engine. For best results, have this issue diagnosed and repaired at the earliest possible moment.

What repairs can fix the P0270 code?

  • Repairing or replacing wiring or connectors that are associated with the fuel injector on the number 4 cylinder.

  • Replacing the fuel injector that is associated with the number 4 cylinder.

  • Replacing the powertrain control module

Additional comments regarding the P0270 code

Wildlife such as rats, squirrels, chipmunks, and even birds can nest up under your engine cover or in other areas of the engine bay. These animals will oftentimes chew on the insulation that covers the wiring for important electrical components of the vehicle. The fuel injectors are very vulnerable to this sort of damage due to their location. Checking for evidence of wildlife during this inspection is a great idea.

Need help with a P0270 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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