P0268 OBD-II Trouble Code: Cylinder number 3 Injector Circuit High

P0268 code definition

Cylinder number 3 Injector Circuit High

What the P0268 code means

P0268 is an OBD-II diagnostic trouble code that is stored when the engine control module (ECM) detects that the cylinder number 3 injector circuit has a high resistance short circuit to power or short to ground.

What causes the P0268 code?

• The number three cylinder injector circuit has a short somewhere in the circuit from the ECM to the injector. This includes the wiring and connections.

• The number three injector is shorted electrically internally causing the circuit high current condition.

• The fuel injector pins are bent or broken in the injector or harness connection causing a short to power or ground.

• The injector wiring is shorted to power or ground (this may also short out components).

• The injector control module or ECM has a shorted internal circuit.

What are the symptoms of the P0268 code?

• The Check Engine Light will be illuminated and code P0268 set in ECM memory and freeze frame.

• The engine will run rough and low on power due to the inoperative injector.

• The engine will have a misfire causing a buck or jerk and a rough idle.

• The engine may lack some power during acceleration when the misfire is active if the short is intermittent.

• The Engine may stall or have other drivability symptoms related to a misfiring defective injector.

If the short is on a main harness, then there may be other circuits having issues if the short is to another circuit.

How does a mechanic diagnose the P0268 code?

1. Scans codes and documents the freeze frame data in order to verify the problem

2. Clears the engine trouble codes and road tests the vehicle to verify concern and code returns

3. Runs an injector electrical self test to verify fault to number 3 injector or harness circuit (following the pinpoint test procedures for the vehicle’s application)

4. Disconnects the injector and measure resistances of the injector to see if the injector is shorted internally (following the pinpoint tests for the vehicle)

5. Disconnects the ECM or injector module and measures the wires’ resistances from the injector connector to the ECM or injector module connector and ground to see if harness is shorted

6. Replaces the injector or ECM injector module as needed if the failure is inside the injector or control module (following the pinpoint tests)

Common mistakes when diagnosing the P0268 code?

• Failing to verify the code returns after scanning and deleting the code
• Failing to check the fuel injector harness resistances before replacing the injector

How serious is the P0268 code?

• A misfiring cylinder can cause the engine to run lean on the failed cylinder. The ECM or injector module may have an internal short failure that may lead to more failures or total loss of all injection control.

What repairs can fix the P0268 code?

• Replacing the injector if it has shorted and failed the resistance tests (should be installed with new injector seals)

• Repairing the wiring or connections between the injector and ECM or injector module for a shorted harness

• Replacing the ECM or injector module, depending on application, for an internal short or if the injector shorted the internal circuit

Additional comments for consideration regarding the P0268 code

Code P0268 is triggered when the ECM or injector module sees the number 3 injector resistance or milliamp draw is high due to a circuit short and turns on the light and sets the code. On some shorts the injector may short internally and also short out the control module. This would require the replacement of the injector and control module plus verification that the harness is not shorted.

Need help with a P0268 code?

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