P0282 code: Cylinder 8 Injector Circuit Low
P0282 means cylinder 8 Injector Circuit Low. The code says where to look, not what failed — the fix depends on which cause your car actually has.
What P0282 means
Found on V8 and larger engines, P0282 reports that the cylinder 8 injector control circuit measured below the voltage the ECM expects when driving that injector. The classic low-side causes are a harness wire shorted to ground, an open circuit, or an injector coil that has shorted internally and pulls the circuit down. It's important to separate this from a mechanically clogged injector: deposits block fuel without changing circuit voltage, so they set misfire codes rather than circuit codes like this one. Diagnosis benefits from the cylinder-specific callout — measure cylinder 8's injector resistance, compare with any healthy cylinder, and inspect its stretch of harness. When the injector actually stops firing, P0208 (cylinder 8 injector circuit) and P0308 (cylinder 8 misfire) typically join it. Cylinder 8's location varies with the manufacturer's bank-numbering scheme, so consult your engine's diagram first.
P0282 symptoms
- Misfire isolated to cylinder 8
- Mildly rough idle — a V8 can partially mask one dead cylinder
- Loss of power, most obvious under hard acceleration or towing
- Check-engine light, which may flash during active misfire
- Occasionally symptom-free if the fault is intermittent
What it costs to fix P0282
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 |
Cylinder 8 usually sits at the back of a bank, often the hardest injector to reach — V8s requiring intake removal and direct-injection engines with premium injectors land at the high end. A wiring or connector repair, once located, is cheap.
The price swings on which cause it turns out to be — so confirm the cause before paying. Diagnose P0282 for my exact vehicle →
How to fix P0282
Moderate — doable at home with common tools and patience
- Check whether other injectors flagged too
Scan every module and list any injector circuit codes beyond P0282. Several cylinders on one bank reporting at once points to something they share — the feed fuse or relay, or a common harness section — while cylinder 8 standing alone points at its own injector or wiring leg. Confirm which corner of the engine it occupies before going further.
- Wiggle the rear harness with the engine idling
On many V8 numbering schemes cylinder 8 sits at the back of a bank, where the loom runs close to the firewall and exhaust heat. With misfire counts or live data on screen, flex that section gently; a stumble or a jump in cylinder 8 misfires marks the spot where insulation has worn through to metal.
- Ohm injector 8, then scope it if the numbers are close
Compare injector 8's resistance with a healthy one first — a clearly lower reading means shorted windings. If they match, back-probe the control wire with a lab scope (port injection only): a normal trace drops near zero while the driver is on and spikes sharply at shut-off. A stunted spike suggests a weak coil; a trace stuck at ground means a grounded wire.
- Swap injector 8 to another position
If results are still borderline, move injector 8 to a neighbouring spot on the same rail and put that injector in its place, using new O-rings. Code changes to the new cylinder's number: the injector is bad. P0282 stays put: the fault lives in the harness or the ECM driver, not in the part you were about to buy.
- Replace what failed and verify the ECM driver
Fit a correctly matched injector or repair the grounded wire, clear codes, and drive through the freeze-frame conditions. If the code returns with a new injector and a harness that tests clean, the driver inside the ECM is what's left; drivers can fail after feeding a shorted coil, and module repair or replacement is a job for a shop with programming tools.
DIY or shop? Reaching cylinder 8 is the real hurdle: on many V8s it's tucked against the firewall, so even unplugging the injector can mean working blind with a mirror. Resistance checks, a wiggle test, and a careful harness repair are well within a home mechanic's reach once you get there. Injector swaps need fuel-pressure relief and sometimes intake removal. If you don't own a scope and the readings are ambiguous, or the code survives a new injector, have a shop test the ECM driver before anyone orders a module.
Tools for the DIY steps: OBD-II scanner with misfire counters · Digital multimeter · Lab scope with back-probe leads · Inspection mirror and flashlight · Fuel injector O-ring kit
Not sure which step applies to your car? Get the likely cause for your exact vehicle before buying anything for P0282.
Start a case with P0282 and your car. Redline weighs these causes against what your car shows, and names the check that would settle it before you buy parts.
Can I drive with P0282?
Redline can’t determine from a symptom or code alone whether your car is safe to drive.
P0282: common questions
What is the ECM actually detecting with P0282?
Voltage on the cylinder 8 injector circuit below the expected range as the injector is pulsed. That's the electrical signature of a short to ground, a break in the wiring, or an injector coil that has shorted internally — not of dirty fuel or a clogged nozzle.
How do I confirm whether the injector is bad?
Two tests settle it. First, measure the injector's resistance and compare with the other seven — a shorted or open reading condemns it. Second, swap it with a neighboring cylinder's injector: if the code follows the part, replace the injector; if it stays on cylinder 8, repair the wiring.
Can I keep driving my truck with P0282?
The code alone can't say whether the car should be driven. Load amplifies the misfire and the raw-fuel dose to the catalytic converter, so arrange the repair promptly. A flashing light means stop driving and get it diagnosed.
Why did P0308 set at the same time?
P0308 is cylinder 8's misfire code — the mechanical consequence of the electrical fault P0282 describes. The injector isn't being driven correctly, so the cylinder misses. Repair the circuit and the misfire code should stop recurring.
Related trouble codes
Don’t have a scanner yet? A ~$25 Bluetooth adapter reads codes like P0282 from your phone. See our guide to the best OBD2 Bluetooth adapters. Run a repair shop? See Redline for shops.
Generic OBD-II reference. Manufacturer-specific behavior varies. Confirm with a scan tool and, for safety-related codes, a professional inspection. Cost ranges are reference ranges, not quotes.
Seeing P0282 on your car?
Every problem becomes a Case. Tell Redline what the car is doing: it shows what the evidence supports, what’s still missing, and what to check next, before you approve a repair.
“Inner pad ~1 mm. Outer pad 3 mm.”
Next: check the slide pins move freely before buying parts.