OBD codes / P0268
P0268
ModerateCylinder 3 Injector Circuit High
An injector circuit fault typically means cylinder 3 isn't burning its fuel, and that fuel ends up in the exhaust where it can overheat the catalytic converter. Limit driving to short, gentle trips until repaired, and stop altogether if the check-engine light flashes.
What this code means
P0268 sets when the ECM detects higher-than-expected voltage on the cylinder 3 injector control circuit. The two broad explanations are a short to battery voltage in the wiring, or excess resistance — a corroded connector, a partially broken wire, or an injector winding that has failed open all raise the circuit's voltage signature. This makes it fundamentally different from a clogged injector, which is a fuel-flow problem the circuit monitor can't see. Only cylinder 3 is flagged, so a resistance comparison or a swap test against a healthy cylinder pins down the failing part quickly. Its companions are P0203 (injector circuit) and P0303 (misfire), both for the same cylinder. And because cylinder numbering conventions vary between manufacturers, double-check where cylinder 3 physically sits on your engine.
Symptoms you might notice
- Cylinder 3 misfire or complete dropout
- Rough idle and engine vibration
- Sluggish acceleration and worse fuel economy
- Check-engine light; flashing indicates an active, catalyst-threatening misfire
- Intermittent versions may set the code without drivability complaints
What it costs to fix
Typical range: $60–$450 · about ~0.5–2 hrs of labor
| If the cause is… | Part | Labor |
|---|---|---|
| Fuel injector (single) | $50–$300 | ~0.5–2 hrs |
| Wiring/connector repair | $5–$50 | ~0.5–2 hrs |
A connector cleaning or terminal repair sits at the low end. Injector replacement costs more and varies with access — V-engines that hide injectors under the intake, and direct-injection engines with premium injectors, push toward the high end.
The price swings on which cause it turns out to be — so confirm the cause before paying. Diagnose P0268 for my exact vehicle →
Frequently asked
What makes a circuit read 'high'?
Two main things: a short that connects the circuit to battery voltage, or added resistance from corrosion, a damaged terminal, or an open injector winding. Both distort the voltage pattern the ECM expects when it fires the cylinder 3 injector, and it sets P0268 in response.
Do I need to replace the injector for P0268?
Not necessarily. Many P0268 cases trace to the connector or harness rather than the injector itself. Test the injector's resistance first — only replace it if it reads open or well out of line with the other cylinders.
The code keeps returning after clearing. Why?
Circuit faults set again as soon as the ECM sees the bad voltage, so clearing without repairing just restarts the clock. If it returns intermittently, suspect a connection that changes with heat and vibration — a corroded pin or a chafed wire that only touches sometimes.
Is driving with P0268 going to damage anything?
The engine itself tolerates a dead cylinder briefly, but the catalytic converter doesn't like the unburned fuel a misfiring cylinder sends its way. Prolonged driving risks an expensive converter failure, so schedule the repair promptly.
Seeing P0268 on your car? Get a diagnosis specific to your exact year, make and model.
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Generic OBD-II reference. Manufacturer-specific behavior varies — confirm with a scan tool and, for safety-related codes, a professional inspection.