P0282
Universal (All Makes) Vehicle (OBD-II)
Severity: ModerateWhat Does This Error Mean?
P0282 means the fuel injector circuit for Cylinder 7 is reading a low voltage or current signal — wait, actually that's P0279. P0282 is the low-circuit code for Cylinder 8. The ECM monitors the electrical response when it fires each injector. A weaker-than-expected signal on Cylinder 8's circuit triggers P0282. Causes range from a bad connector or broken wire to a failed injector or ECM driver. Symptoms include rough idle, hesitation, reduced power, and often a Cylinder 8 misfire code alongside it.
Affected Models
- All vehicles 1996+ with 8 or more cylinders
- Common in V8, V10, and V12 engines
- Common in high-mileage trucks, muscle cars, and full-size SUVs
- More frequent in vehicles where the rear-bank wiring harness has aged or been damaged
Common Causes
- Corroded or loose connector at the Cylinder 8 fuel injector
- Broken or chafed wire between the ECM and the Cylinder 8 injector
- Open-circuit Cylinder 8 fuel injector that no longer conducts current
- ECM injector driver failure for Cylinder 8
- Blown fuse or failed relay in the injector supply circuit
How to Fix It
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Locate the Cylinder 8 injector. On V8 engines it's typically at the back of the driver-side bank. Unplug the connector and inspect both halves for corrosion, bent pins, and a secure fit. Clean with electrical contact cleaner and reconnect fully.
The rearmost injectors on V8s are the hardest to access and often the least frequently inspected — connector corrosion here is common.
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Trace the Cylinder 8 injector wiring from the connector back toward the ECM. Look for insulation damage near the exhaust manifold, heat shields, firewall grommets, or any metal edge the harness contacts. A bare wire touching ground triggers a low-circuit code.
Hold the harness and feel for stiffness or brittleness — age and heat cause insulation to crack even when no visible damage is apparent.
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Test the Cylinder 8 injector resistance with a multimeter. Unplug the connector and probe the two injector terminals directly. Normal reading is 10–18 ohms for most vehicles. An open (infinite) reading means the injector coil has broken internally and the injector needs replacement.
An open injector won't fire at all — Cylinder 8 gets zero fuel and will misfire hard.
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Check the injector supply fuse and relay. If multiple injector-circuit codes appeared at once (e.g., P0279, P0282), the fault is likely in the shared power circuit — fuse or relay — rather than in the individual injectors.
A failed relay can cause intermittent power loss to an entire bank of injectors, producing multiple low-circuit codes simultaneously.
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If all components test within spec and P0282 persists, have a shop test the ECM's Cylinder 8 driver output with a breakout box or scope. Confirm the fault is truly in the ECM before authorizing a replacement — ECM misdiagnosis is a common and expensive mistake.
Some specialist shops can repair individual ECM driver circuits, which is often cheaper than replacing the entire module.
When to Call a Professional
If the connector and wiring look fine but P0282 keeps coming back, professional circuit testing is needed. ECM failure is a possible but less common cause — confirm it with proper diagnostic tools before spending money on a new module. If Cylinder 8 is also misfiring, limit driving until repaired to prevent catalytic converter damage.
Frequently Asked Questions
How do I know which cylinder is Cylinder 8 on my engine?
Cylinder numbering varies by manufacturer. On most American V8 engines (GM, Ford, Chrysler), Cylinder 8 is at the rear of the driver-side bank. Always confirm using your vehicle's service manual or a quick online search for your specific engine's cylinder layout.
Can a single blown fuse cause P0282?
Yes. Fuel injectors are typically grouped on shared fuses. If the fuse for the group covering Cylinder 8 blows, the ECM will see a low-circuit signal for all injectors in that group. Multiple injector codes appearing at once is a strong hint to check the fuse first.
How much does it cost to fix P0282?
Connector cleaning or repair: Free to $50. Wiring harness repair: $100–$300. Injector replacement: $150–$400 installed. ECM repair or replacement: $300–$1,200+.