Fuel and air

P0264 — Cylinder 2 Injector Circuit Low

Severity: medium Drive with care, to a shop

What P0264 means

The engine control module fires each fuel injector by switching its circuit to ground, and it monitors the voltage in that circuit. P0264 is set when the voltage in the cylinder 2 injector circuit is lower than expected. Typical causes are a wire shorted to ground, a corroded connector, or a shorted injector coil. Some sources label this code as a cylinder 2 contribution/balance fault, but that description belongs to P0266.

Symptoms

  • Check Engine light on
  • Rough idle
  • Misfire or hesitation under acceleration
  • Loss of power
  • Higher fuel consumption
  • Possible companion misfire code P0302
  • Hard starting

Possible causes

  1. Failed cylinder 2 fuel injector (shorted internal coil)
  2. Damaged or chafed wiring, injector control wire shorted to ground
  3. Corroded or loose terminals in the injector connector
  4. Moisture or oil inside the injector connector
  5. Faulty injector driver in the engine computer (uncommon)

How to diagnose

  1. Scan all codes and freeze frame data, and look for misfire codes such as P0302 or other injector circuit codes.
  2. Inspect the cylinder 2 injector connector and harness for chafing, oil, moisture, corrosion and a secure latch.
  3. Unplug the injector and measure its coil resistance, comparing it to the factory spec and to the other injectors.
  4. Check for power at the connector with the ignition on.
  5. Test the control wire from the connector to the computer for opens and shorts to ground.
  6. Swap the injector with another cylinder and see whether the code follows the injector.
  7. Check the control signal with a scope or noid light.
  8. Suspect the engine computer only after everything else has been ruled out.

Common fixes

  • Clean the terminals and restore a secure injector connector fit
  • Repair the damaged wiring or replace the connector
  • Replace the faulty cylinder 2 injector
  • Repair or replace the engine computer if the driver is confirmed bad
  • Clear the code and road test to confirm it does not return

Questions and answers

What does P0264 mean?

The engine computer found low voltage in the control circuit of the cylinder 2 fuel injector. The usual culprits are wiring, the connector or the injector itself.

Can I drive with code P0264?

Only briefly and carefully until it is repaired. The cylinder may misfire, which raises fuel use and can damage the catalytic converter.

How do I tell if it is the injector or the wiring?

Measure the injector's resistance and test the wire back to the computer. You can also swap the injector with a neighboring cylinder: if the code moves to that cylinder, the injector is bad.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.