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P0204: Injector Circuit Malfunction - Cylinder 4

HighPowertrainDIY: Advanced

Can you still drive? Not recommended. Continuous driving with a dead injector can overheat and destroy the catalytic converter.

What Does P0204 Mean?

Code P0204 indicates that the ECM has detected a problem with the fuel injector circuit on cylinder 4. The electrical signal to the injector is outside the expected range, meaning the injector may not be opening or closing properly. This directly affects combustion in cylinder 4 and overall engine performance.

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Common Causes

  • Defective fuel injector
  • Damaged wiring harness to cylinder 4 injector
  • Corroded connector at the injector
  • ECM injector driver failure

Symptoms

  • Check engine light on
  • Cylinder 4 misfire
  • Rough running engine
  • Loss of power and acceleration
  • Increased exhaust emissions

Diagnostic Steps

  1. 1Read freeze frame data and look for companion P0304 misfire code
  2. 2Test injector resistance with a multimeter
  3. 3Verify ECM signal with a noid light at the injector connector
  4. 4Swap cylinder 4 injector with another cylinder to confirm diagnosis
  5. 5Check the wiring harness for damage between the ECM and injector

Recommended Parts & Tools

Estimated Repair Cost

TypeEstimated Cost
Total Repair Cost Range$150 - $600

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Get a detailed AI diagnosis for code P0204 specific to your vehicle. Includes step-by-step repair instructions, exact parts needed, and a cost breakdown tailored to your make and model.

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Commonly Affected Vehicles

Ford FusionChevrolet MalibuHonda CR-VToyota RAV4

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Frequently Asked Questions

Can a clogged injector cause P0204?

A clogged injector alone usually does not trigger P0204, which is an electrical circuit code. A clogged injector is more likely to cause a lean misfire code. P0204 specifically means the injector circuit has an electrical fault.

What if the code comes back after replacing the injector?

If the code returns after injector replacement, the problem is likely in the wiring harness or the ECM injector driver circuit. Further electrical testing is needed.

Community Fix Reports

Community reports are user-submitted and not verified by Auto AI Buddy. Results may vary.

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