OBD codes / P0283
P0283
ModerateCylinder 8 Injector Circuit High
The remaining seven cylinders will carry the engine, but cylinder 8's unburned fuel still heads for the catalytic converter on that bank. Keep driving brief and gentle until the circuit is repaired; a flashing check-engine light means park it.
What this code means
A circuit-high fault on the cylinder 8 injector: the ECM saw voltage above its expected window while driving this injector, which points to a short to battery voltage or to excess resistance from corrosion, a failing connector terminal, or an injector winding that has gone open. Codes in this family judge the electrical path only — fuel-side problems like a gummed-up nozzle produce misfires without disturbing circuit voltage, so P0283 steers you firmly toward wiring and electrics. The code applies to engines with eight or more cylinders, and with that many identical injector circuits, comparing readings across cylinders is the fastest diagnostic shortcut available. Related codes for the same cylinder are P0208 (injector circuit) and P0308 (misfire). Cylinder numbering on V8s differs between manufacturers — one brand's cylinder 8 is another's cylinder 5 — so verify the layout for your engine.
Symptoms you might notice
- Cylinder 8 misfire or dropout
- Subtle to moderate idle roughness
- Reduced power, sluggish response under load
- Check-engine light, flashing if the misfire is severe
- May store silently when the fault is intermittent
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 |
If the culprit is a corroded pin or damaged wire, expect the low end. Injector replacement costs more — especially on V8s where intake manifold removal is required for access, and on direct-injection engines whose injectors carry a premium.
The price swings on which cause it turns out to be — so confirm the cause before paying. Diagnose P0283 for my exact vehicle →
Frequently asked
What does 'circuit high' point to?
Higher-than-expected voltage on the cylinder 8 injector circuit — usually from a short to battery voltage, or from resistance introduced by a corroded connector, a bad terminal, or an injector coil that has failed open. It's an electrical-path fault, not a fuel-quality issue.
Is P0283 expensive to fix?
Often not: connector cleaning or a wire repair is cheap once found. The cost rises if the injector needs replacing, and access is the wildcard — an injector buried under a V8's intake manifold, or a direct-injection injector, costs meaningfully more in parts and labor.
Why is my code intermittent?
Loose or corroded connections are temperature- and vibration-sensitive, so the circuit can test fine in the driveway and fail on the highway. That flickering behavior is diagnostic gold: it points at the connector and harness, and a wiggle test while monitoring the circuit often finds the spot.
Can I tow with this code active?
Best not to. Load increases fuel demand on every cylinder, magnifying the misfire and the amount of unburned fuel hitting the catalytic converter. Keep the vehicle lightly loaded and trips short until cylinder 8's circuit is fixed.
Seeing P0283 on your car? Get a diagnosis specific to your exact year, make and model.
Diagnose P0283 for my vehicleRelated trouble codes
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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.