P0280Generic code

P0280 Code: Cylinder 7 Injector Circuit High

The P0280 code means the control circuit of the cylinder 7 injector reads a higher voltage than the computer expects, usually because of an open circuit or a short to voltage. The injector never gets to open. You can drive with caution, but the engine will be running on one cylinder less.

Severity
Medium
Can I keep driving?
Yes, but with caution
Estimated cost
$20 to $600
Difficulty
Medium
System
Fuel Injection
Applies to
All OBD2 vehicles

Updated Reviewed by Renzo Chacca

On this page

What the P0280 code means

When the computer commands an injector to open, it connects the injector control wire to ground, and the voltage should fall to nearly zero. If it stays high, the circuit is open (the injector coil or the wire is broken) or the control wire is touching 12 V. Either way the injector does not open and cylinder 7 gets no fuel. That is what sets the P0280 code.

The quickest check is to unplug injector 7 and plug an injector test light (noid light) or an LED lamp into the connector in its place. When you crank the engine, it should flash. If it flashes, the wiring and the computer are working and the problem is the injector or its connector. If it does not flash, follow the wire back to the computer.

Cylinder numbering depends on the manufacturer. On most inline engines, cylinder 1 is the one closest to the timing belt or chain. On V engines, the odd and even cylinders are usually on different banks. Confirm the numbering in the service manual before you take anything apart.

P0280 code symptoms

  • Check engine light on.
  • Engine shaking or a rough idle.
  • Loss of power.
  • Black or white smoke (diesel) or misfires (gas engine).
  • The engine may keep running on one cylinder less.

Likely causes of the P0280 code

  1. Injector 7 connector unplugged or broken. The most common cause.
  2. Injector 7 coil open. Infinite resistance.
  3. Control wire cut.
  4. Control wire shorted to 12 V from rubbing against another wire.
  5. Computer driver open. Uncommon.

How to diagnose the P0280 code step by step

  1. Confirm the cylinder with the scan tool (misfire counters, or per-cylinder fuel quantity corrections on a diesel).
  2. Measure the resistance of injector 7 and compare it with the other injectors.
  3. Check for the 12 V supply at the connector with the key on.
  4. Check the control wire. Continuity to the computer, and isolation from ground and from 12 V.
  5. Use an injector test light (noid light) to see whether the computer is sending the command.
  6. Clear the codes and recreate the condition to confirm the repair.

How to fix the P0280 code

  • Repair the damaged wire or connector.
  • Replace the injector if its coil is open or shorted.
  • Repair the supply (fuse, relay, wire).
  • If the computer driver is damaged, replace the shorted injector first.
  • Clear the codes and verify on a road test.

Technical reference data

  • High-impedance gasoline injector: 11 to 18 ohms.
  • Low-impedance injector: 2 to 5 ohms.
  • Typical supply: 12 V from a relay or the computer. The computer switches the ground to open the injector.
  • Piezo common rail diesel injectors are not tested with an ohmmeter the same way. Follow the manufacturer procedure.
  • These values are for orientation only. Check the manufacturer data for your engine.

Brand-specific notes

On many vehicles the injector supply shares a fuse with the ignition coils. If several codes show up at once, check that fuse first.

Frequently asked questions about P0280

Can I drive with a P0280 code?
With caution and only for a short time. A cylinder that is not contributing makes the engine shake and increases wear.
Which cylinder is number 7?
Cylinder numbering depends on the manufacturer. On most inline engines, cylinder 1 is the one closest to the timing belt or chain. On V engines, the odd and even cylinders are usually on different banks. Confirm the numbering in the service manual before you take anything apart.
Does the injector have to be replaced?
Only if the tests confirm it. In many cases the cause of the P0280 code is in the wiring, not in the injector.
How much does it cost to fix P0280?
Between $20 and $600 on a gas engine. On a diesel, an injector can cost $150 to $800 plus the coding.
What does the P0280 code mean?
It is a generic OBD2 code that means the control circuit of the cylinder 7 injector reads a higher voltage than expected. It points to an open circuit or a short to voltage.
Will a P0280 code clear itself?
Only if the cause is intermittent, such as a connector that loses contact now and then. A broken wire or a dead injector coil will keep the light on until it is repaired.

Related codes

Questions about the P0280 code

There are no questions about this code yet. Tell us about your case: vehicle, symptoms and what you have already checked.