P0284 moderate

Injector Circuit Low - Cylinder 8

The P0284 code means the vehicle's onboard diagnostic system has detected: Injector Circuit Low - Cylinder 8. This is a moderate severity code.

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Keep driving?
Short distances only
DIY difficulty
hard
Estimated cost
$150 - $600 (parts and labor)
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Common Symptoms

  • Check Engine Light illuminated
  • Cylinder 8 misfire
  • Rough idle
  • Rich exhaust condition

Probable Causes (Ranked by Likelihood)

  • Short to ground in cylinder 8 injector wiring Very High
  • Internally shorted injector High
  • Corroded connector Moderate
  • PCM driver fault Low

Step-by-Step Diagnostic Procedure

  1. Measure cylinder 8 injector resistance.

  2. Check wiring for short to ground.

  3. Inspect connector for corrosion or fuel contamination.

  4. Compare resistance to other injectors.

Frequently Asked Questions

What causes circuit low on cylinder 8?

A short to ground in the wiring or an internally shorted injector coil allows more current than expected to flow.

Can engine heat cause wiring shorts?

Yes, V8 engines run hot, and wiring near exhaust manifolds can degrade over time, leading to shorts.

How much does a V8 injector cost?

Port injection injectors cost $30-$80 each. GDI injectors cost $80-$200 each. Labor varies by accessibility.

Sources

This page is built from documented references. Verify against your own service info before repair work.

P0284 on Diesel, EV & Equipment

The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:

Duramax serious Cylinder 8 Contribution / Balance Fault Power Stroke moderate Cylinder 8 Contribution/Balance

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